diff --git a/.build/jsonSchema.ts b/.build/jsonSchema.ts
index 6fd8ca3f5..ab3d1f2fa 100644
--- a/.build/jsonSchema.ts
+++ b/.build/jsonSchema.ts
@@ -1,7 +1,10 @@
 import { load, JSON_SCHEMA } from 'js-yaml';
 import assert from 'node:assert';
 import Ajv2019, { type JSONSchemaType } from 'ajv/dist/2019.js';
-import type { MermaidConfig, BaseDiagramConfig } from '../packages/mermaid/src/config.type.js';
+import type {
+  MermaidConfigWithDefaults,
+  BaseDiagramConfig,
+} from '../packages/mermaid/src/config.type.js';
 
 /**
  * All of the keys in the mermaid config that have a mermaid diagram config.
@@ -36,7 +39,7 @@ const MERMAID_CONFIG_DIAGRAM_KEYS = [
  * @param mermaidConfigSchema - The Mermaid JSON Schema to use.
  * @returns The default mermaid config object.
  */
-function generateDefaults(mermaidConfigSchema: JSONSchemaType<MermaidConfig>) {
+function generateDefaults(mermaidConfigSchema: JSONSchemaType<MermaidConfigWithDefaults>) {
   const ajv = new Ajv2019({
     useDefaults: true,
     allowUnionTypes: true,
@@ -105,20 +108,23 @@ function generateDefaults(mermaidConfigSchema: JSONSchemaType<MermaidConfig>) {
   return mermaidDefaultConfig;
 }
 
-export const loadSchema = (src: string, filename: string): JSONSchemaType<MermaidConfig> => {
+export const loadSchema = (
+  src: string,
+  filename: string
+): JSONSchemaType<MermaidConfigWithDefaults> => {
   const jsonSchema = load(src, {
     filename,
     // only allow JSON types in our YAML doc (will probably be default in YAML 1.3)
     // e.g. `true` will be parsed a boolean `true`, `True` will be parsed as string `"True"`.
     schema: JSON_SCHEMA,
-  }) as JSONSchemaType<MermaidConfig>;
+  }) as JSONSchemaType<MermaidConfigWithDefaults>;
   return jsonSchema;
 };
 
-export const getDefaults = (schema: JSONSchemaType<MermaidConfig>) => {
+export const getDefaults = (schema: JSONSchemaType<MermaidConfigWithDefaults>) => {
   return `export default ${JSON.stringify(generateDefaults(schema), undefined, 2)};`;
 };
 
-export const getSchema = (schema: JSONSchemaType<MermaidConfig>) => {
+export const getSchema = (schema: JSONSchemaType<MermaidConfigWithDefaults>) => {
   return `export default ${JSON.stringify(schema, undefined, 2)};`;
 };
diff --git a/.esbuild/jsonSchemaPlugin.ts b/.esbuild/jsonSchemaPlugin.ts
index e90c185ab..a4206cddd 100644
--- a/.esbuild/jsonSchemaPlugin.ts
+++ b/.esbuild/jsonSchemaPlugin.ts
@@ -1,5 +1,5 @@
 import type { JSONSchemaType } from 'ajv/dist/2019.js';
-import type { MermaidConfig } from '../packages/mermaid/src/config.type.js';
+import type { MermaidConfigWithDefaults } from '../packages/mermaid/src/config.type.js';
 import { readFile } from 'node:fs/promises';
 import { getDefaults, getSchema, loadSchema } from '../.build/jsonSchema.js';
 
@@ -12,13 +12,13 @@ import { getDefaults, getSchema, loadSchema } from '../.build/jsonSchema.js';
 export const jsonSchemaPlugin = {
   name: 'json-schema-plugin',
   setup(build) {
-    let schema: JSONSchemaType<MermaidConfig> | undefined = undefined;
+    let schema: JSONSchemaType<MermaidConfigWithDefaults> | undefined = undefined;
     let content = '';
 
     build.onLoad({ filter: /config\.schema\.yaml$/ }, async (args) => {
       // Load the file from the file system
       const source = await readFile(args.path, 'utf8');
-      const resolvedSchema: JSONSchemaType<MermaidConfig> =
+      const resolvedSchema: JSONSchemaType<MermaidConfigWithDefaults> =
         content === source && schema ? schema : loadSchema(source, args.path);
       if (content !== source) {
         content = source;
diff --git a/docs/config/setup/modules/config.md b/docs/config/setup/modules/config.md
index ff5aa7640..6ff06560b 100644
--- a/docs/config/setup/modules/config.md
+++ b/docs/config/setup/modules/config.md
@@ -10,7 +10,7 @@
 
 ### defaultConfig
 
-• `Const` **defaultConfig**: `MermaidConfig`
+• `Const` **defaultConfig**: `MermaidConfigWithDefaults`
 
 #### Defined in
 
@@ -26,9 +26,9 @@ Pushes in a directive to the configuration
 
 #### Parameters
 
-| Name        | Type                                     | Description              |
-| :---------- | :--------------------------------------- | :----------------------- |
-| `directive` | `PartialObjectDeep`<`MermaidConfig`, {}> | The directive to push in |
+| Name        | Type                                                 | Description              |
+| :---------- | :--------------------------------------------------- | :----------------------- |
+| `directive` | `PartialObjectDeep`<`MermaidConfigWithDefaults`, {}> | The directive to push in |
 
 #### Returns
 
@@ -42,7 +42,7 @@ Pushes in a directive to the configuration
 
 ### getConfig
 
-▸ **getConfig**(): `MermaidConfig`
+▸ **getConfig**(): `MermaidConfigWithDefaults`
 
 ## getConfig
 
@@ -54,7 +54,7 @@ Pushes in a directive to the configuration
 
 #### Returns
 
-`MermaidConfig`
+`MermaidConfigWithDefaults`
 
 The currentConfig
 
@@ -66,7 +66,7 @@ The currentConfig
 
 ### getSiteConfig
 
-▸ **getSiteConfig**(): `MermaidConfig`
+▸ **getSiteConfig**(): `MermaidConfigWithDefaults`
 
 ## getSiteConfig
 
@@ -78,7 +78,7 @@ The currentConfig
 
 #### Returns
 
-`MermaidConfig`
+`MermaidConfigWithDefaults`
 
 The siteConfig
 
@@ -108,9 +108,9 @@ The siteConfig
 
 #### Parameters
 
-| Name     | Type            | Default value | Description                                                                                                                                                   |
-| :------- | :-------------- | :------------ | :------------------------------------------------------------------------------------------------------------------------------------------------------------ |
-| `config` | `MermaidConfig` | `siteConfig`  | base set of values, which currentConfig could be **reset** to. Defaults to the current siteConfig (e.g returned by [getSiteConfig](config.md#getsiteconfig)). |
+| Name     | Type                        | Default value | Description                                                                                                                                                   |
+| :------- | :-------------------------- | :------------ | :------------------------------------------------------------------------------------------------------------------------------------------------------------ |
+| `config` | `MermaidConfigWithDefaults` | `siteConfig`  | base set of values, which currentConfig could be **reset** to. Defaults to the current siteConfig (e.g returned by [getSiteConfig](config.md#getsiteconfig)). |
 
 #### Returns
 
@@ -157,9 +157,9 @@ options in-place
 
 #### Parameters
 
-| Name   | Type                                     |
-| :----- | :--------------------------------------- |
-| `conf` | `PartialObjectDeep`<`MermaidConfig`, {}> |
+| Name   | Type                                                 |
+| :----- | :--------------------------------------------------- |
+| `conf` | `PartialObjectDeep`<`MermaidConfigWithDefaults`, {}> |
 
 #### Returns
 
@@ -173,7 +173,7 @@ options in-place
 
 ### setConfig
 
-▸ **setConfig**(`conf`): `MermaidConfig`
+▸ **setConfig**(`conf`): `MermaidConfigWithDefaults`
 
 ## setConfig
 
@@ -187,13 +187,13 @@ corresponding siteConfig value.
 
 #### Parameters
 
-| Name   | Type                                     | Description                 |
-| :----- | :--------------------------------------- | :-------------------------- |
-| `conf` | `PartialObjectDeep`<`MermaidConfig`, {}> | The potential currentConfig |
+| Name   | Type                                                 | Description                 |
+| :----- | :--------------------------------------------------- | :-------------------------- |
+| `conf` | `PartialObjectDeep`<`MermaidConfigWithDefaults`, {}> | The potential currentConfig |
 
 #### Returns
 
-`MermaidConfig`
+`MermaidConfigWithDefaults`
 
 The currentConfig merged with the sanitized conf
 
@@ -205,7 +205,7 @@ The currentConfig merged with the sanitized conf
 
 ### setSiteConfig
 
-▸ **setSiteConfig**(`conf`): `MermaidConfig`
+▸ **setSiteConfig**(`conf`): `MermaidConfigWithDefaults`
 
 ## setSiteConfig
 
@@ -220,13 +220,13 @@ function _Default value: At default, will mirror Global Config_
 
 #### Parameters
 
-| Name   | Type                                     | Description                                 |
-| :----- | :--------------------------------------- | :------------------------------------------ |
-| `conf` | `PartialObjectDeep`<`MermaidConfig`, {}> | The base currentConfig to use as siteConfig |
+| Name   | Type                                                 | Description                                 |
+| :----- | :--------------------------------------------------- | :------------------------------------------ |
+| `conf` | `PartialObjectDeep`<`MermaidConfigWithDefaults`, {}> | The base currentConfig to use as siteConfig |
 
 #### Returns
 
-`MermaidConfig`
+`MermaidConfigWithDefaults`
 
 The new siteConfig
 
@@ -238,18 +238,18 @@ The new siteConfig
 
 ### updateCurrentConfig
 
-▸ **updateCurrentConfig**(`siteCfg`, `_directives`): `MermaidConfig`
+▸ **updateCurrentConfig**(`siteCfg`, `_directives`): `MermaidConfigWithDefaults`
 
 #### Parameters
 
-| Name          | Type                                        |
-| :------------ | :------------------------------------------ |
-| `siteCfg`     | `MermaidConfig`                             |
-| `_directives` | `PartialObjectDeep`<`MermaidConfig`, {}>\[] |
+| Name          | Type                                                    |
+| :------------ | :------------------------------------------------------ |
+| `siteCfg`     | `MermaidConfigWithDefaults`                             |
+| `_directives` | `PartialObjectDeep`<`MermaidConfigWithDefaults`, {}>\[] |
 
 #### Returns
 
-`MermaidConfig`
+`MermaidConfigWithDefaults`
 
 #### Defined in
 
@@ -259,17 +259,17 @@ The new siteConfig
 
 ### updateSiteConfig
 
-▸ **updateSiteConfig**(`conf`): `MermaidConfig`
+▸ **updateSiteConfig**(`conf`): `MermaidConfigWithDefaults`
 
 #### Parameters
 
-| Name   | Type                                     |
-| :----- | :--------------------------------------- |
-| `conf` | `PartialObjectDeep`<`MermaidConfig`, {}> |
+| Name   | Type                                                 |
+| :----- | :--------------------------------------------------- |
+| `conf` | `PartialObjectDeep`<`MermaidConfigWithDefaults`, {}> |
 
 #### Returns
 
-`MermaidConfig`
+`MermaidConfigWithDefaults`
 
 #### Defined in
 
diff --git a/docs/config/setup/modules/defaultConfig.md b/docs/config/setup/modules/defaultConfig.md
index d3495bc0c..965a5fad3 100644
--- a/docs/config/setup/modules/defaultConfig.md
+++ b/docs/config/setup/modules/defaultConfig.md
@@ -20,7 +20,7 @@
 
 ### default
 
-• `Const` **default**: `RequiredDeep`<`MermaidConfig`>
+• `Const` **default**: `RequiredDeep`<`MermaidConfigWithDefaults`>
 
 Default mermaid configuration options.
 
diff --git a/docs/config/setup/modules/mermaidAPI.md b/docs/config/setup/modules/mermaidAPI.md
index c370c0122..6d1d356fa 100644
--- a/docs/config/setup/modules/mermaidAPI.md
+++ b/docs/config/setup/modules/mermaidAPI.md
@@ -32,7 +32,7 @@ Renames and re-exports [mermaidAPI](mermaidAPI.md#mermaidapi)
 
 ### mermaidAPI
 
-• `Const` **mermaidAPI**: `Readonly`<{ `defaultConfig`: `MermaidConfig` = configApi.defaultConfig; `getConfig`: () => `MermaidConfig` = configApi.getConfig; `getDiagramFromText`: (`text`: `string`, `metadata`: `Pick`<`DiagramMetadata`, `"title"`>) => `Promise`<`Diagram`> ; `getSiteConfig`: () => `MermaidConfig` = configApi.getSiteConfig; `globalReset`: () => `void` ; `initialize`: (`options`: `PartialObjectDeep`<`MermaidConfig`, {}>) => `void` ; `parse`: (`text`: `string`, `parseOptions`: [`ParseOptions`](../interfaces/mermaidAPI.ParseOptions.md) & { `suppressErrors`: `true` }) => `Promise`<[`ParseResult`](../interfaces/mermaidAPI.ParseResult.md) | `false`>(`text`: `string`, `parseOptions?`: [`ParseOptions`](../interfaces/mermaidAPI.ParseOptions.md)) => `Promise`<[`ParseResult`](../interfaces/mermaidAPI.ParseResult.md)> ; `render`: (`id`: `string`, `text`: `string`, `svgContainingElement?`: `Element`) => `Promise`<[`RenderResult`](../interfaces/mermaidAPI.RenderResult.md)> ; `reset`: () => `void` ; `setConfig`: (`conf`: `PartialObjectDeep`<`MermaidConfig`, {}>) => `MermaidConfig` = configApi.setConfig; `updateSiteConfig`: (`conf`: `PartialObjectDeep`<`MermaidConfig`, {}>) => `MermaidConfig` = configApi.updateSiteConfig }>
+• `Const` **mermaidAPI**: `Readonly`<{ `defaultConfig`: `MermaidConfigWithDefaults` = configApi.defaultConfig; `getConfig`: () => `MermaidConfigWithDefaults` = configApi.getConfig; `getDiagramFromText`: (`text`: `string`, `metadata`: `Pick`<`DiagramMetadata`, `"title"`>) => `Promise`<`Diagram`> ; `getSiteConfig`: () => `MermaidConfigWithDefaults` = configApi.getSiteConfig; `globalReset`: () => `void` ; `initialize`: (`options`: `PartialObjectDeep`<`MermaidConfigWithDefaults`, {}>) => `void` ; `parse`: (`text`: `string`, `parseOptions`: [`ParseOptions`](../interfaces/mermaidAPI.ParseOptions.md) & { `suppressErrors`: `true` }) => `Promise`<[`ParseResult`](../interfaces/mermaidAPI.ParseResult.md) | `false`>(`text`: `string`, `parseOptions?`: [`ParseOptions`](../interfaces/mermaidAPI.ParseOptions.md)) => `Promise`<[`ParseResult`](../interfaces/mermaidAPI.ParseResult.md)> ; `render`: (`id`: `string`, `text`: `string`, `svgContainingElement?`: `Element`) => `Promise`<[`RenderResult`](../interfaces/mermaidAPI.RenderResult.md)> ; `reset`: () => `void` ; `setConfig`: (`conf`: `PartialObjectDeep`<`MermaidConfigWithDefaults`, {}>) => `MermaidConfigWithDefaults` = configApi.setConfig; `updateSiteConfig`: (`conf`: `PartialObjectDeep`<`MermaidConfigWithDefaults`, {}>) => `MermaidConfigWithDefaults` = configApi.updateSiteConfig }>
 
 ## mermaidAPI configuration defaults
 
@@ -169,7 +169,7 @@ Create the user styles
 
 | Name        | Type                                                                | Description                                                                                                               |
 | :---------- | :------------------------------------------------------------------ | :------------------------------------------------------------------------------------------------------------------------ |
-| `config`    | `MermaidConfig`                                                     | configuration that has style and theme settings to use                                                                    |
+| `config`    | `MermaidConfigWithDefaults`                                         | configuration that has style and theme settings to use                                                                    |
 | `classDefs` | `undefined` \| `null` \| `Record`<`string`, `DiagramStyleClassDef`> | the classDefs in the diagram text. Might be null if none were defined. Usually is the result of a call to getClasses(...) |
 
 #### Returns
@@ -192,7 +192,7 @@ the string with all the user styles
 
 | Name        | Type                                                      |
 | :---------- | :-------------------------------------------------------- |
-| `config`    | `MermaidConfig`                                           |
+| `config`    | `MermaidConfigWithDefaults`                               |
 | `graphType` | `string`                                                  |
 | `classDefs` | `undefined` \| `Record`<`string`, `DiagramStyleClassDef`> |
 | `svgId`     | `string`                                                  |
diff --git a/packages/mermaid-zenuml/src/mermaidUtils.ts b/packages/mermaid-zenuml/src/mermaidUtils.ts
index 623685879..e054a3ddd 100644
--- a/packages/mermaid-zenuml/src/mermaidUtils.ts
+++ b/packages/mermaid-zenuml/src/mermaidUtils.ts
@@ -1,4 +1,4 @@
-import type { MermaidConfig } from 'mermaid';
+import type { MermaidConfigWithDefaults } from 'mermaid';
 
 const warning = (s: string) => {
   // Todo remove debug code
@@ -27,7 +27,7 @@ export const log: Record<keyof typeof LEVELS, typeof console.log> = {
 };
 
 export let setLogLevel: (level: keyof typeof LEVELS | number | string) => void;
-export let getConfig: () => MermaidConfig;
+export let getConfig: () => MermaidConfigWithDefaults;
 export let sanitizeText: (str: string) => string;
 // eslint-disable @typescript-eslint/no-explicit-any
 export let setupGraphViewbox: (
diff --git a/packages/mermaid/scripts/create-types-from-json-schema.mts b/packages/mermaid/scripts/create-types-from-json-schema.mts
index 317d6b547..d2f2c971f 100644
--- a/packages/mermaid/scripts/create-types-from-json-schema.mts
+++ b/packages/mermaid/scripts/create-types-from-json-schema.mts
@@ -25,7 +25,7 @@ import prettier from 'prettier';
 const Ajv2019 = _Ajv2019 as unknown as typeof _Ajv2019.default;
 
 // !!! -- The config.type.js file is created by this script -- !!!
-import type { MermaidConfig } from '../src/config.type.js';
+import type { MermaidConfigWithDefaults } from '../src/config.type.js';
 
 // options for running the main command
 const verifyOnly = process.argv.includes('--verify');
@@ -33,7 +33,7 @@ const verifyOnly = process.argv.includes('--verify');
 const git = process.argv.includes('--git');
 
 /**
- * Loads the MermaidConfig JSON schema YAML file.
+ * Loads the MermaidConfigWithDefaults JSON schema YAML file.
  *
  * @returns The loaded JSON Schema, use {@link validateSchema} to confirm it is a valid JSON Schema.
  */
@@ -55,7 +55,9 @@ async function loadJsonSchemaFromYaml() {
  * @param jsonSchema - The value to validate as JSON Schema 2019-09
  * @throws {Error} if the given object is invalid.
  */
-function validateSchema(jsonSchema: unknown): asserts jsonSchema is JSONSchemaType<MermaidConfig> {
+function validateSchema(
+  jsonSchema: unknown
+): asserts jsonSchema is JSONSchemaType<MermaidConfigWithDefaults> {
   if (typeof jsonSchema !== 'object') {
     throw new Error(`jsonSchema param is not an object: actual type is ${typeof jsonSchema}`);
   }
@@ -85,7 +87,7 @@ function validateSchema(jsonSchema: unknown): asserts jsonSchema is JSONSchemaTy
  *
  * @param mermaidConfigSchema - The input JSON Schema.
  */
-async function generateTypescript(mermaidConfigSchema: JSONSchemaType<MermaidConfig>) {
+async function generateTypescript(mermaidConfigSchema: JSONSchemaType<MermaidConfigWithDefaults>) {
   /**
    * Replace all usages of `allOf` with `extends`.
    *
@@ -119,7 +121,7 @@ async function generateTypescript(mermaidConfigSchema: JSONSchemaType<MermaidCon
 
   const typescriptFile = await compile(
     modifiedSchema as unknown as JSONSchema, // json-schema-to-typescript only allows JSON Schema 4 as input type
-    'MermaidConfig',
+    'MermaidConfigWithDefaults',
     {
       additionalProperties: false, // in JSON Schema 2019-09, these are called `unevaluatedProperties`
       unreachableDefinitions: true, // definition for FontConfig is unreachable
@@ -173,6 +175,7 @@ async function main() {
   }
 
   const configJsonSchema = await loadJsonSchemaFromYaml();
+  // TODO: Add code to mark objects with default values as required
 
   removeProp(configJsonSchema, 'default');
 
diff --git a/packages/mermaid/src/config.spec.ts b/packages/mermaid/src/config.spec.ts
index 32cf704ca..6b1d34953 100644
--- a/packages/mermaid/src/config.spec.ts
+++ b/packages/mermaid/src/config.spec.ts
@@ -1,6 +1,7 @@
 /* eslint-disable @typescript-eslint/no-non-null-assertion */
+import { expect, it } from 'vitest';
 import * as configApi from './config.js';
-import type { MermaidConfig, PartialMermaidConfig } from './config.type.js';
+import type { MermaidConfig, MermaidConfigWithDefaults } from './config.type.js';
 
 describe('when working with site config', () => {
   beforeEach(() => {
@@ -22,15 +23,15 @@ describe('when working with site config', () => {
       securityLevel: 'strict', // can't be changed
       fontSize: 12345, // can't be changed
       secure: [...configApi.defaultConfig.secure!, 'fontSize'],
-    } as MermaidConfig;
+    } as MermaidConfigWithDefaults;
     configApi.setSiteConfig(config_0);
-    const directive: PartialMermaidConfig = {
+    const directive: MermaidConfig = {
       fontFamily: 'baf',
       // fontSize and securityLevel shouldn't be changed
       fontSize: 54321,
       securityLevel: 'loose',
     };
-    const cfg: MermaidConfig = configApi.updateCurrentConfig(config_0, [directive]);
+    const cfg: MermaidConfigWithDefaults = configApi.updateCurrentConfig(config_0, [directive]);
     expect(cfg.fontFamily).toEqual(directive.fontFamily);
     expect(cfg.fontSize).toBe(config_0.fontSize);
     expect(cfg.securityLevel).toBe(config_0.securityLevel);
diff --git a/packages/mermaid/src/config.ts b/packages/mermaid/src/config.ts
index 0d849a475..5fb47f6b7 100644
--- a/packages/mermaid/src/config.ts
+++ b/packages/mermaid/src/config.ts
@@ -1,27 +1,27 @@
 import assignWithDepth from './assignWithDepth.js';
-import type { MermaidConfig, PartialMermaidConfig } from './config.type.js';
+import type { MermaidConfigWithDefaults, MermaidConfig } from './config.type.js';
 import config from './defaultConfig.js';
 import { log } from './logger.js';
 import theme from './themes/index.js';
 import { sanitizeDirective } from './utils/sanitizeDirective.js';
 
-export const defaultConfig: MermaidConfig = Object.freeze(config);
+export const defaultConfig: MermaidConfigWithDefaults = Object.freeze(config);
 
-let siteConfig: MermaidConfig = assignWithDepth({}, defaultConfig);
-let configFromInitialize: PartialMermaidConfig;
-let directives: PartialMermaidConfig[] = [];
-let currentConfig: MermaidConfig = assignWithDepth({}, defaultConfig);
+let siteConfig: MermaidConfigWithDefaults = assignWithDepth({}, defaultConfig);
+let configFromInitialize: MermaidConfig;
+let directives: MermaidConfig[] = [];
+let currentConfig: MermaidConfigWithDefaults = assignWithDepth({}, defaultConfig);
 
 export const updateCurrentConfig = (
-  siteCfg: MermaidConfig,
-  _directives: PartialMermaidConfig[]
+  siteCfg: MermaidConfigWithDefaults,
+  _directives: MermaidConfig[]
 ) => {
   // start with config being the siteConfig
-  let cfg: MermaidConfig = assignWithDepth({}, siteCfg);
+  let cfg: MermaidConfigWithDefaults = assignWithDepth({}, siteCfg);
   // let sCfg = assignWithDepth(defaultConfig, siteConfigDelta);
 
   // Join directives
-  let sumOfDirectives: PartialMermaidConfig = {};
+  let sumOfDirectives: MermaidConfig = {};
   for (const d of _directives) {
     sanitize(d);
     // Apply the data from the directive where the overrides the themeVariables
@@ -61,7 +61,7 @@ export const updateCurrentConfig = (
  * @param conf - The base currentConfig to use as siteConfig
  * @returns The new siteConfig
  */
-export const setSiteConfig = (conf: PartialMermaidConfig): MermaidConfig => {
+export const setSiteConfig = (conf: MermaidConfig): MermaidConfigWithDefaults => {
   siteConfig = assignWithDepth({}, defaultConfig);
   siteConfig = assignWithDepth(siteConfig, conf);
 
@@ -75,11 +75,11 @@ export const setSiteConfig = (conf: PartialMermaidConfig): MermaidConfig => {
   return siteConfig;
 };
 
-export const saveConfigFromInitialize = (conf: PartialMermaidConfig): void => {
+export const saveConfigFromInitialize = (conf: MermaidConfig): void => {
   configFromInitialize = assignWithDepth({}, conf);
 };
 
-export const updateSiteConfig = (conf: PartialMermaidConfig): MermaidConfig => {
+export const updateSiteConfig = (conf: MermaidConfig): MermaidConfigWithDefaults => {
   siteConfig = assignWithDepth(siteConfig, conf);
   updateCurrentConfig(siteConfig, directives);
 
@@ -96,7 +96,7 @@ export const updateSiteConfig = (conf: PartialMermaidConfig): MermaidConfig => {
  *
  * @returns The siteConfig
  */
-export const getSiteConfig = (): MermaidConfig => {
+export const getSiteConfig = (): MermaidConfigWithDefaults => {
   return assignWithDepth({}, siteConfig);
 };
 /**
@@ -113,7 +113,7 @@ export const getSiteConfig = (): MermaidConfig => {
  * @param conf - The potential currentConfig
  * @returns The currentConfig merged with the sanitized conf
  */
-export const setConfig = (conf: PartialMermaidConfig): MermaidConfig => {
+export const setConfig = (conf: MermaidConfig): MermaidConfigWithDefaults => {
   checkConfig(conf);
   assignWithDepth(currentConfig, conf);
 
@@ -131,7 +131,7 @@ export const setConfig = (conf: PartialMermaidConfig): MermaidConfig => {
  *
  * @returns The currentConfig
  */
-export const getConfig = (): MermaidConfig => {
+export const getConfig = (): MermaidConfigWithDefaults => {
   return assignWithDepth({}, currentConfig);
 };
 /**
@@ -188,7 +188,7 @@ export const sanitize = (options: any) => {
  *
  * @param directive - The directive to push in
  */
-export const addDirective = (directive: PartialMermaidConfig) => {
+export const addDirective = (directive: MermaidConfig) => {
   sanitizeDirective(directive);
 
   // If the directive has a fontFamily, but no themeVariables, add the fontFamily to the themeVariables
@@ -239,7 +239,7 @@ const issueWarning = (warning: ConfigWarningStrings) => {
   issuedWarnings[warning] = true;
 };
 
-const checkConfig = (config: PartialMermaidConfig) => {
+const checkConfig = (config: MermaidConfig) => {
   if (!config) {
     return;
   }
diff --git a/packages/mermaid/src/config.type.ts b/packages/mermaid/src/config.type.ts
index 512e86712..fd0397592 100644
--- a/packages/mermaid/src/config.type.ts
+++ b/packages/mermaid/src/config.type.ts
@@ -24,7 +24,7 @@
  * ```
  *
  *
- * This interface was referenced by `MermaidConfig`'s JSON-Schema
+ * This interface was referenced by `MermaidConfigWithDefaults`'s JSON-Schema
  * via the `definition` "FontCalculator".
  */
 export type FontCalculator = () => Partial<FontConfig>;
@@ -32,7 +32,7 @@ export type FontCalculator = () => Partial<FontConfig>;
  * Picks the color of the sankey diagram links, using the colors of the source and/or target of the links.
  *
  *
- * This interface was referenced by `MermaidConfig`'s JSON-Schema
+ * This interface was referenced by `MermaidConfigWithDefaults`'s JSON-Schema
  * via the `definition` "SankeyLinkColor".
  */
 export type SankeyLinkColor = 'source' | 'target' | 'gradient';
@@ -42,7 +42,7 @@ export type SankeyLinkColor = 'source' | 'target' | 'gradient';
  * See <https://github.com/d3/d3-sankey#alignments>.
  *
  *
- * This interface was referenced by `MermaidConfig`'s JSON-Schema
+ * This interface was referenced by `MermaidConfigWithDefaults`'s JSON-Schema
  * via the `definition` "SankeyNodeAlignment".
  */
 export type SankeyNodeAlignment = 'left' | 'right' | 'center' | 'justify';
@@ -51,18 +51,18 @@ export type SankeyNodeAlignment = 'left' | 'right' | 'center' | 'justify';
  */
 export type DOMPurifyConfiguration = import('dompurify').Config;
 /**
- * MermaidConfig with all fields optional
+ * MermaidConfigWithDefaults with all fields optional
  *
- * This interface was referenced by `MermaidConfig`'s JSON-Schema
- * via the `definition` "PartialMermaidConfig".
+ * This interface was referenced by `MermaidConfigWithDefaults`'s JSON-Schema
+ * via the `definition` "MermaidConfig".
  */
-export type PartialMermaidConfig = import('type-fest').PartialDeep<MermaidConfig>;
+export type MermaidConfig = import('type-fest').PartialDeep<MermaidConfigWithDefaults>;
 /**
  * The font size to use
  */
 export type CSSFontSize = string | number;
 
-export interface MermaidConfig {
+export interface MermaidConfigWithDefaults {
   /**
    * Theme, the CSS style sheet.
    * You may also use `themeCSS` to override this value.
@@ -184,7 +184,7 @@ export interface MermaidConfig {
 /**
  * The object containing configurations specific for flowcharts
  *
- * This interface was referenced by `MermaidConfig`'s JSON-Schema
+ * This interface was referenced by `MermaidConfigWithDefaults`'s JSON-Schema
  * via the `definition` "FlowchartDiagramConfig".
  */
 export interface FlowchartDiagramConfig extends BaseDiagramConfig {
@@ -255,7 +255,7 @@ export interface FlowchartDiagramConfig extends BaseDiagramConfig {
   wrappingWidth: number;
 }
 /**
- * This interface was referenced by `MermaidConfig`'s JSON-Schema
+ * This interface was referenced by `MermaidConfigWithDefaults`'s JSON-Schema
  * via the `definition` "BaseDiagramConfig".
  */
 export interface BaseDiagramConfig {
@@ -271,7 +271,7 @@ export interface BaseDiagramConfig {
 /**
  * The object containing configurations specific for sequence diagrams
  *
- * This interface was referenced by `MermaidConfig`'s JSON-Schema
+ * This interface was referenced by `MermaidConfigWithDefaults`'s JSON-Schema
  * via the `definition` "SequenceDiagramConfig".
  */
 export interface SequenceDiagramConfig extends BaseDiagramConfig {
@@ -414,7 +414,7 @@ export interface SequenceDiagramConfig extends BaseDiagramConfig {
  * The object containing configurations specific for gantt diagrams
  *
  *
- * This interface was referenced by `MermaidConfig`'s JSON-Schema
+ * This interface was referenced by `MermaidConfigWithDefaults`'s JSON-Schema
  * via the `definition` "GanttDiagramConfig".
  */
 export interface GanttDiagramConfig extends BaseDiagramConfig {
@@ -499,7 +499,7 @@ export interface GanttDiagramConfig extends BaseDiagramConfig {
  * The object containing configurations specific for journey diagrams
  *
  *
- * This interface was referenced by `MermaidConfig`'s JSON-Schema
+ * This interface was referenced by `MermaidConfigWithDefaults`'s JSON-Schema
  * via the `definition` "JourneyDiagramConfig".
  */
 export interface JourneyDiagramConfig extends BaseDiagramConfig {
@@ -577,7 +577,7 @@ export interface JourneyDiagramConfig extends BaseDiagramConfig {
   sectionColours?: string[];
 }
 /**
- * This interface was referenced by `MermaidConfig`'s JSON-Schema
+ * This interface was referenced by `MermaidConfigWithDefaults`'s JSON-Schema
  * via the `definition` "TimelineDiagramConfig".
  */
 export interface TimelineDiagramConfig extends BaseDiagramConfig {
@@ -657,7 +657,7 @@ export interface TimelineDiagramConfig extends BaseDiagramConfig {
   disableMulticolor?: boolean;
 }
 /**
- * This interface was referenced by `MermaidConfig`'s JSON-Schema
+ * This interface was referenced by `MermaidConfigWithDefaults`'s JSON-Schema
  * via the `definition` "ClassDiagramConfig".
  */
 export interface ClassDiagramConfig extends BaseDiagramConfig {
@@ -692,7 +692,7 @@ export interface ClassDiagramConfig extends BaseDiagramConfig {
 /**
  * The object containing configurations specific for entity relationship diagrams
  *
- * This interface was referenced by `MermaidConfig`'s JSON-Schema
+ * This interface was referenced by `MermaidConfigWithDefaults`'s JSON-Schema
  * via the `definition` "StateDiagramConfig".
  */
 export interface StateDiagramConfig extends BaseDiagramConfig {
@@ -731,7 +731,7 @@ export interface StateDiagramConfig extends BaseDiagramConfig {
 /**
  * The object containing configurations specific for entity relationship diagrams
  *
- * This interface was referenced by `MermaidConfig`'s JSON-Schema
+ * This interface was referenced by `MermaidConfigWithDefaults`'s JSON-Schema
  * via the `definition` "ErDiagramConfig".
  */
 export interface ErDiagramConfig extends BaseDiagramConfig {
@@ -777,7 +777,7 @@ export interface ErDiagramConfig extends BaseDiagramConfig {
   fontSize?: number;
 }
 /**
- * This interface was referenced by `MermaidConfig`'s JSON-Schema
+ * This interface was referenced by `MermaidConfigWithDefaults`'s JSON-Schema
  * via the `definition` "PieDiagramConfig".
  */
 export interface PieDiagramConfig extends BaseDiagramConfig {
@@ -788,7 +788,7 @@ export interface PieDiagramConfig extends BaseDiagramConfig {
   textPosition?: number;
 }
 /**
- * This interface was referenced by `MermaidConfig`'s JSON-Schema
+ * This interface was referenced by `MermaidConfigWithDefaults`'s JSON-Schema
  * via the `definition` "QuadrantChartConfig".
  */
 export interface QuadrantChartConfig extends BaseDiagramConfig {
@@ -868,7 +868,7 @@ export interface QuadrantChartConfig extends BaseDiagramConfig {
 /**
  * This object contains configuration specific to XYCharts
  *
- * This interface was referenced by `MermaidConfig`'s JSON-Schema
+ * This interface was referenced by `MermaidConfigWithDefaults`'s JSON-Schema
  * via the `definition` "XYChartConfig".
  */
 export interface XYChartConfig extends BaseDiagramConfig {
@@ -906,7 +906,7 @@ export interface XYChartConfig extends BaseDiagramConfig {
 /**
  * This object contains configuration for XYChart axis config
  *
- * This interface was referenced by `MermaidConfig`'s JSON-Schema
+ * This interface was referenced by `MermaidConfigWithDefaults`'s JSON-Schema
  * via the `definition` "XYChartAxisConfig".
  */
 export interface XYChartAxisConfig {
@@ -958,7 +958,7 @@ export interface XYChartAxisConfig {
 /**
  * The object containing configurations specific for req diagrams
  *
- * This interface was referenced by `MermaidConfig`'s JSON-Schema
+ * This interface was referenced by `MermaidConfigWithDefaults`'s JSON-Schema
  * via the `definition` "RequirementDiagramConfig".
  */
 export interface RequirementDiagramConfig extends BaseDiagramConfig {
@@ -975,7 +975,7 @@ export interface RequirementDiagramConfig extends BaseDiagramConfig {
 /**
  * The object containing configurations specific for mindmap diagrams
  *
- * This interface was referenced by `MermaidConfig`'s JSON-Schema
+ * This interface was referenced by `MermaidConfigWithDefaults`'s JSON-Schema
  * via the `definition` "MindmapDiagramConfig".
  */
 export interface MindmapDiagramConfig extends BaseDiagramConfig {
@@ -983,7 +983,7 @@ export interface MindmapDiagramConfig extends BaseDiagramConfig {
   maxNodeWidth: number;
 }
 /**
- * This interface was referenced by `MermaidConfig`'s JSON-Schema
+ * This interface was referenced by `MermaidConfigWithDefaults`'s JSON-Schema
  * via the `definition` "GitGraphDiagramConfig".
  */
 export interface GitGraphDiagramConfig extends BaseDiagramConfig {
@@ -1007,7 +1007,7 @@ export interface GitGraphDiagramConfig extends BaseDiagramConfig {
   arrowMarkerAbsolute?: boolean;
 }
 /**
- * This interface was referenced by `MermaidConfig`'s JSON-Schema
+ * This interface was referenced by `MermaidConfigWithDefaults`'s JSON-Schema
  * via the `definition` "NodeLabel".
  */
 export interface NodeLabel {
@@ -1019,7 +1019,7 @@ export interface NodeLabel {
 /**
  * The object containing configurations specific for c4 diagrams
  *
- * This interface was referenced by `MermaidConfig`'s JSON-Schema
+ * This interface was referenced by `MermaidConfigWithDefaults`'s JSON-Schema
  * via the `definition` "C4DiagramConfig".
  */
 export interface C4DiagramConfig extends BaseDiagramConfig {
@@ -1400,7 +1400,7 @@ export interface C4DiagramConfig extends BaseDiagramConfig {
 /**
  * The object containing configurations specific for sankey diagrams.
  *
- * This interface was referenced by `MermaidConfig`'s JSON-Schema
+ * This interface was referenced by `MermaidConfigWithDefaults`'s JSON-Schema
  * via the `definition` "SankeyDiagramConfig".
  */
 export interface SankeyDiagramConfig extends BaseDiagramConfig {
@@ -1432,7 +1432,7 @@ export interface SankeyDiagramConfig extends BaseDiagramConfig {
 /**
  * The object containing configurations specific for packet diagrams.
  *
- * This interface was referenced by `MermaidConfig`'s JSON-Schema
+ * This interface was referenced by `MermaidConfigWithDefaults`'s JSON-Schema
  * via the `definition` "PacketDiagramConfig".
  */
 export interface PacketDiagramConfig extends BaseDiagramConfig {
@@ -1464,14 +1464,14 @@ export interface PacketDiagramConfig extends BaseDiagramConfig {
 /**
  * The object containing configurations specific for block diagrams.
  *
- * This interface was referenced by `MermaidConfig`'s JSON-Schema
+ * This interface was referenced by `MermaidConfigWithDefaults`'s JSON-Schema
  * via the `definition` "BlockDiagramConfig".
  */
 export interface BlockDiagramConfig extends BaseDiagramConfig {
   padding?: number;
 }
 /**
- * This interface was referenced by `MermaidConfig`'s JSON-Schema
+ * This interface was referenced by `MermaidConfigWithDefaults`'s JSON-Schema
  * via the `definition` "FontConfig".
  */
 export interface FontConfig {
diff --git a/packages/mermaid/src/defaultConfig.ts b/packages/mermaid/src/defaultConfig.ts
index 76a8152b7..01ac8a0b5 100644
--- a/packages/mermaid/src/defaultConfig.ts
+++ b/packages/mermaid/src/defaultConfig.ts
@@ -1,8 +1,5 @@
-import type { RequiredDeep } from 'type-fest';
-
+import type { MermaidConfigWithDefaults } from './config.type.js';
 import theme from './themes/index.js';
-import type { MermaidConfig } from './config.type.js';
-
 // Uses our custom Vite jsonSchemaPlugin to load only the default values from
 // our JSON Schema
 // @ts-expect-error This file is automatically generated via a custom Vite plugin
@@ -15,7 +12,7 @@ import defaultConfigJson from './schemas/config.schema.yaml?only-defaults=true';
  * Non-JSON JS default values are listed in this file, e.g. functions, or
  * `undefined` (explicitly set so that `configKeys` finds them).
  */
-const config: RequiredDeep<MermaidConfig> = {
+const config: MermaidConfigWithDefaults = {
   ...defaultConfigJson,
   // Set, even though they're `undefined` so that `configKeys` finds these keys
   // TODO: Should we replace these with `null` so that they can go in the JSON Schema?
diff --git a/packages/mermaid/src/diagram-api/detectType.ts b/packages/mermaid/src/diagram-api/detectType.ts
index cfff2fbb3..8d7d52357 100644
--- a/packages/mermaid/src/diagram-api/detectType.ts
+++ b/packages/mermaid/src/diagram-api/detectType.ts
@@ -1,4 +1,4 @@
-import type { MermaidConfig } from '../config.type.js';
+import type { MermaidConfigWithDefaults } from '../config.type.js';
 import { UnknownDiagramError } from '../errors.js';
 import { log } from '../logger.js';
 import { anyCommentRegex, directiveRegex, frontMatterRegex } from './regexes.js';
@@ -33,7 +33,7 @@ export const detectors: Record<string, DetectorRecord> = {};
  * @param config - The mermaid config.
  * @returns A graph definition key
  */
-export const detectType = function (text: string, config?: MermaidConfig): string {
+export const detectType = function (text: string, config?: MermaidConfigWithDefaults): string {
   text = text
     .replace(frontMatterRegex, '')
     .replace(directiveRegex, '')
diff --git a/packages/mermaid/src/diagram-api/diagram-orchestration.spec.ts b/packages/mermaid/src/diagram-api/diagram-orchestration.spec.ts
index 1ceda0a46..e90573554 100644
--- a/packages/mermaid/src/diagram-api/diagram-orchestration.spec.ts
+++ b/packages/mermaid/src/diagram-api/diagram-orchestration.spec.ts
@@ -1,5 +1,5 @@
-import { describe, expect, it } from 'vitest';
-import type { MermaidConfig } from '../config.type.js';
+import { describe, expect, it, beforeAll } from 'vitest';
+import type { MermaidConfigWithDefaults } from '../config.type.js';
 import { detectType } from './detectType.js';
 import { addDiagrams } from './diagram-orchestration.js';
 
@@ -50,13 +50,13 @@ describe('diagram-orchestration', () => {
       expect(
         detectType('graph TD; A-->B', {
           flowchart: { defaultRenderer: 'dagre-d3' },
-        } as MermaidConfig)
+        } as MermaidConfigWithDefaults)
       ).toBe('flowchart');
       // flowchart & dagre-d3 => error
       expect(() =>
         detectType('flowchart TD; A-->B', {
           flowchart: { defaultRenderer: 'dagre-d3' },
-        } as MermaidConfig)
+        } as MermaidConfigWithDefaults)
       ).toThrowErrorMatchingInlineSnapshot(
         `[UnknownDiagramError: No diagram type detected matching given configuration for text: flowchart TD; A-->B]`
       );
@@ -65,7 +65,7 @@ describe('diagram-orchestration', () => {
       expect(
         detectType('graph TD; A-->B', {
           flowchart: { defaultRenderer: 'dagre-wrapper' },
-        } as MermaidConfig)
+        } as MermaidConfigWithDefaults)
       ).toBe('flowchart-v2');
       // flowchart ==> flowchart-v2
       expect(detectType('flowchart TD; A-->B')).toBe('flowchart-v2');
@@ -73,13 +73,13 @@ describe('diagram-orchestration', () => {
       expect(
         detectType('flowchart TD; A-->B', {
           flowchart: { defaultRenderer: 'dagre-wrapper' },
-        } as MermaidConfig)
+        } as MermaidConfigWithDefaults)
       ).toBe('flowchart-v2');
       // flowchart && elk ==> flowchart-elk
       expect(
         detectType('flowchart TD; A-->B', {
           flowchart: { defaultRenderer: 'elk' },
-        } as MermaidConfig)
+        } as MermaidConfigWithDefaults)
       ).toBe('flowchart-elk');
     });
 
diff --git a/packages/mermaid/src/diagram-api/frontmatter.ts b/packages/mermaid/src/diagram-api/frontmatter.ts
index 86ea84a25..c8d662c28 100644
--- a/packages/mermaid/src/diagram-api/frontmatter.ts
+++ b/packages/mermaid/src/diagram-api/frontmatter.ts
@@ -1,4 +1,4 @@
-import type { GanttDiagramConfig, PartialMermaidConfig } from '../config.type.js';
+import type { GanttDiagramConfig, MermaidConfig } from '../config.type.js';
 import { frontMatterRegex } from './regexes.js';
 // The "* as yaml" part is necessary for tree-shaking
 import * as yaml from 'js-yaml';
@@ -7,7 +7,7 @@ interface FrontMatterMetadata {
   title?: string;
   // Allows custom display modes. Currently used for compact mode in gantt charts.
   displayMode?: GanttDiagramConfig['displayMode'];
-  config?: PartialMermaidConfig;
+  config?: MermaidConfig;
 }
 
 export interface FrontMatterResult {
diff --git a/packages/mermaid/src/diagram-api/types.ts b/packages/mermaid/src/diagram-api/types.ts
index d4c187891..6ab82bd0d 100644
--- a/packages/mermaid/src/diagram-api/types.ts
+++ b/packages/mermaid/src/diagram-api/types.ts
@@ -2,11 +2,11 @@
 import type * as d3 from 'd3';
 import type { SetRequired } from 'type-fest';
 import type { Diagram } from '../Diagram.js';
-import type { BaseDiagramConfig, PartialMermaidConfig } from '../config.type.js';
+import type { BaseDiagramConfig, MermaidConfig } from '../config.type.js';
 
 export interface DiagramMetadata {
   title?: string;
-  config?: PartialMermaidConfig;
+  config?: MermaidConfig;
 }
 
 export interface InjectUtils {
@@ -78,7 +78,7 @@ export interface DiagramDefinition {
   renderer: DiagramRenderer;
   parser: ParserDefinition;
   styles?: any;
-  init?: (config: PartialMermaidConfig) => void;
+  init?: (config: MermaidConfig) => void;
   injectUtils?: (
     _log: InjectUtils['_log'],
     _setLogLevel: InjectUtils['_setLogLevel'],
@@ -102,7 +102,7 @@ export interface ExternalDiagramDefinition {
   loader: DiagramLoader;
 }
 
-export type DiagramDetector = (text: string, config?: PartialMermaidConfig) => boolean;
+export type DiagramDetector = (text: string, config?: MermaidConfig) => boolean;
 export type DiagramLoader = () => Promise<{ id: string; diagram: DiagramDefinition }>;
 
 /**
diff --git a/packages/mermaid/src/diagrams/block/blockRenderer.ts b/packages/mermaid/src/diagrams/block/blockRenderer.ts
index e6289ad82..9268a15a6 100644
--- a/packages/mermaid/src/diagrams/block/blockRenderer.ts
+++ b/packages/mermaid/src/diagrams/block/blockRenderer.ts
@@ -5,7 +5,7 @@ import {
 } from 'd3';
 import type { Diagram } from '../../Diagram.js';
 import * as configApi from '../../config.js';
-import type { MermaidConfig } from '../../config.type.js';
+import type { MermaidConfigWithDefaults } from '../../config.type.js';
 import insertMarkers from '../../dagre-wrapper/markers.js';
 import { log } from '../../logger.js';
 import { configureSvgSize } from '../../setupGraphViewbox.js';
@@ -75,7 +75,7 @@ export const draw = async function (
     const magicFactor = Math.max(1, Math.round(0.125 * (bounds2.width / bounds2.height)));
     const height = bounds2.height + magicFactor + 10;
     const width = bounds2.width + 10;
-    const { useMaxWidth } = conf as Exclude<MermaidConfig['block'], undefined>;
+    const { useMaxWidth } = conf as Exclude<MermaidConfigWithDefaults['block'], undefined>;
     configureSvgSize(svg, height, width, !!useMaxWidth);
     log.debug('Here Bounds', bounds, bounds2);
     svg.attr(
diff --git a/packages/mermaid/src/diagrams/common/common.spec.ts b/packages/mermaid/src/diagrams/common/common.spec.ts
index d382d0399..86d028939 100644
--- a/packages/mermaid/src/diagrams/common/common.spec.ts
+++ b/packages/mermaid/src/diagrams/common/common.spec.ts
@@ -1,4 +1,5 @@
-import type { MermaidConfig } from '../../config.type.js';
+import { describe, expect, it } from 'vitest';
+import type { MermaidConfigWithDefaults } from '../../config.type.js';
 import { countOccurrence, parseGenericTypes, removeScript, sanitizeText } from './common.js';
 
 describe('when securityLevel is antiscript, all script must be removed', () => {
@@ -68,7 +69,7 @@ describe('Sanitize text', () => {
     const result = sanitizeText(maliciousStr, {
       securityLevel: 'strict',
       flowchart: { htmlLabels: true },
-    } as MermaidConfig);
+    } as MermaidConfigWithDefaults);
     expect(result).not.toContain('javascript:alert(1)');
   });
 });
diff --git a/packages/mermaid/src/diagrams/common/common.ts b/packages/mermaid/src/diagrams/common/common.ts
index 66cc5ff6f..1b44bdfbe 100644
--- a/packages/mermaid/src/diagrams/common/common.ts
+++ b/packages/mermaid/src/diagrams/common/common.ts
@@ -1,5 +1,5 @@
 import DOMPurify from 'dompurify';
-import type { MermaidConfig } from '../../config.type.js';
+import type { MermaidConfigWithDefaults } from '../../config.type.js';
 
 // Remove and ignore br:s
 export const lineBreakRegex = /<br\s*\/?>/gi;
@@ -63,7 +63,7 @@ export const removeScript = (txt: string): string => {
   return sanitizedText;
 };
 
-const sanitizeMore = (text: string, config: MermaidConfig) => {
+const sanitizeMore = (text: string, config: MermaidConfigWithDefaults) => {
   if (config.flowchart?.htmlLabels !== false) {
     const level = config.securityLevel;
     if (level === 'antiscript' || level === 'strict') {
@@ -78,7 +78,7 @@ const sanitizeMore = (text: string, config: MermaidConfig) => {
   return text;
 };
 
-export const sanitizeText = (text: string, config: MermaidConfig): string => {
+export const sanitizeText = (text: string, config: MermaidConfigWithDefaults): string => {
   if (!text) {
     return text;
   }
@@ -94,7 +94,7 @@ export const sanitizeText = (text: string, config: MermaidConfig): string => {
 
 export const sanitizeTextOrArray = (
   a: string | string[] | string[][],
-  config: MermaidConfig
+  config: MermaidConfigWithDefaults
 ): string | string[] => {
   if (typeof a === 'string') {
     return sanitizeText(a, config);
@@ -310,7 +310,10 @@ export const hasKatex = (text: string): boolean => (text.match(katexRegex)?.leng
  * @param config - Configuration for Mermaid
  * @returns Object containing \{width, height\}
  */
-export const calculateMathMLDimensions = async (text: string, config: MermaidConfig) => {
+export const calculateMathMLDimensions = async (
+  text: string,
+  config: MermaidConfigWithDefaults
+) => {
   text = await renderKatex(text, config);
   const divElem = document.createElement('div');
   divElem.innerHTML = text;
@@ -332,7 +335,10 @@ export const calculateMathMLDimensions = async (text: string, config: MermaidCon
  * @param config - Configuration for Mermaid
  * @returns String containing MathML if KaTeX is supported, or an error message if it is not and stylesheets aren't present
  */
-export const renderKatex = async (text: string, config: MermaidConfig): Promise<string> => {
+export const renderKatex = async (
+  text: string,
+  config: MermaidConfigWithDefaults
+): Promise<string> => {
   if (!hasKatex(text)) {
     return text;
   }
diff --git a/packages/mermaid/src/diagrams/mindmap/mindmapRenderer.ts b/packages/mermaid/src/diagrams/mindmap/mindmapRenderer.ts
index 978647994..30c0d764b 100644
--- a/packages/mermaid/src/diagrams/mindmap/mindmapRenderer.ts
+++ b/packages/mermaid/src/diagrams/mindmap/mindmapRenderer.ts
@@ -1,8 +1,8 @@
 import cytoscape from 'cytoscape';
-// @ts-expect-error No types available
+// @ts-ignore Types for cose-bilkent are not present
 import coseBilkent from 'cytoscape-cose-bilkent';
 import { select } from 'd3';
-import type { MermaidConfig } from '../../config.type.js';
+import type { MermaidConfigWithDefaults } from '../../config.type.js';
 import { getConfig } from '../../diagram-api/diagramAPI.js';
 import type { DrawDefinition } from '../../diagram-api/types.js';
 import { log } from '../../logger.js';
@@ -21,7 +21,7 @@ function drawNodes(
   svg: D3Element,
   mindmap: FilledMindMapNode,
   section: number,
-  conf: MermaidConfig
+  conf: MermaidConfigWithDefaults
 ) {
   drawNode(db, svg, mindmap, section, conf);
   if (mindmap.children) {
@@ -64,7 +64,12 @@ function drawEdges(edgesEl: D3Element, cy: cytoscape.Core) {
   });
 }
 
-function addNodes(mindmap: MindmapNode, cy: cytoscape.Core, conf: MermaidConfig, level: number) {
+function addNodes(
+  mindmap: MindmapNode,
+  cy: cytoscape.Core,
+  conf: MermaidConfigWithDefaults,
+  level: number
+) {
   cy.add({
     group: 'nodes',
     data: {
@@ -99,7 +104,10 @@ function addNodes(mindmap: MindmapNode, cy: cytoscape.Core, conf: MermaidConfig,
   }
 }
 
-function layoutMindmap(node: MindmapNode, conf: MermaidConfig): Promise<cytoscape.Core> {
+function layoutMindmap(
+  node: MindmapNode,
+  conf: MermaidConfigWithDefaults
+): Promise<cytoscape.Core> {
   return new Promise((resolve) => {
     // Add temporary render element
     const renderEl = select('body').append('div').attr('id', 'cy').attr('style', 'display:none');
diff --git a/packages/mermaid/src/diagrams/mindmap/svgDraw.ts b/packages/mermaid/src/diagrams/mindmap/svgDraw.ts
index c84a7b16c..8baf84957 100644
--- a/packages/mermaid/src/diagrams/mindmap/svgDraw.ts
+++ b/packages/mermaid/src/diagrams/mindmap/svgDraw.ts
@@ -3,7 +3,7 @@ import { createText } from '../../rendering-util/createText.js';
 import type { FilledMindMapNode, MindmapDB } from './mindmapTypes.js';
 import type { Point } from '../../types.js';
 import { parseFontSize } from '../../utils.js';
-import type { MermaidConfig } from '../../config.type.js';
+import type { MermaidConfigWithDefaults } from '../../config.type.js';
 
 const MAX_SECTIONS = 12;
 
@@ -180,7 +180,7 @@ export const drawNode = function (
   elem: D3Element,
   node: FilledMindMapNode,
   fullSection: number,
-  conf: MermaidConfig
+  conf: MermaidConfigWithDefaults
 ): number {
   const htmlLabels = conf.htmlLabels;
   const section = fullSection % (MAX_SECTIONS - 1);
diff --git a/packages/mermaid/src/diagrams/pie/pieRenderer.ts b/packages/mermaid/src/diagrams/pie/pieRenderer.ts
index fb386863b..8c07a2ad7 100644
--- a/packages/mermaid/src/diagrams/pie/pieRenderer.ts
+++ b/packages/mermaid/src/diagrams/pie/pieRenderer.ts
@@ -6,7 +6,7 @@ import { getConfig } from '../../diagram-api/diagramAPI.js';
 import { cleanAndMerge, parseFontSize } from '../../utils.js';
 import type { DrawDefinition, Group, SVG } from '../../diagram-api/types.js';
 import type { D3Section, PieDB, Sections } from './pieTypes.js';
-import type { MermaidConfig, PieDiagramConfig } from '../../config.type.js';
+import type { MermaidConfigWithDefaults, PieDiagramConfig } from '../../config.type.js';
 import { selectSvgElement } from '../../rendering-util/selectSvgElement.js';
 
 const createPieArcs = (sections: Sections): d3.PieArcDatum<D3Section>[] => {
@@ -38,7 +38,7 @@ const createPieArcs = (sections: Sections): d3.PieArcDatum<D3Section>[] => {
 export const draw: DrawDefinition = (text, id, _version, diagObj) => {
   log.debug('rendering pie chart\n' + text);
   const db = diagObj.db as PieDB;
-  const globalConfig: MermaidConfig = getConfig();
+  const globalConfig: MermaidConfigWithDefaults = getConfig();
   const pieConfig: Required<PieDiagramConfig> = cleanAndMerge(db.getConfig(), globalConfig.pie);
   const MARGIN = 40;
   const LEGEND_RECT_SIZE = 18;
diff --git a/packages/mermaid/src/diagrams/timeline/timelineRenderer.ts b/packages/mermaid/src/diagrams/timeline/timelineRenderer.ts
index 2f1f15689..f37cb3331 100644
--- a/packages/mermaid/src/diagrams/timeline/timelineRenderer.ts
+++ b/packages/mermaid/src/diagrams/timeline/timelineRenderer.ts
@@ -6,7 +6,7 @@ import { log } from '../../logger.js';
 import { getConfig } from '../../diagram-api/diagramAPI.js';
 import { setupGraphViewbox } from '../../setupGraphViewbox.js';
 import type { Diagram } from '../../Diagram.js';
-import type { MermaidConfig } from '../../config.type.js';
+import type { MermaidConfigWithDefaults } from '../../config.type.js';
 
 interface Block<TDesc, TSection> {
   number: number;
@@ -241,7 +241,7 @@ export const drawTasks = function (
   masterX: number,
   masterY: number,
   maxTaskHeight: number,
-  conf: MermaidConfig,
+  conf: MermaidConfigWithDefaults,
   maxEventCount: number,
   maxEventLineLength: number,
   maxSectionHeight: number,
@@ -318,7 +318,7 @@ export const drawEvents = function (
   sectionColor: number,
   masterX: number,
   masterY: number,
-  conf: MermaidConfig
+  conf: MermaidConfigWithDefaults
 ) {
   let maxEventHeight = 0;
   const eventBeginY = masterY;
diff --git a/packages/mermaid/src/docs/.vitepress/theme/mermaid.ts b/packages/mermaid/src/docs/.vitepress/theme/mermaid.ts
index 47e238692..0931c4d73 100644
--- a/packages/mermaid/src/docs/.vitepress/theme/mermaid.ts
+++ b/packages/mermaid/src/docs/.vitepress/theme/mermaid.ts
@@ -1,9 +1,13 @@
-import mermaid, { type MermaidConfig } from 'mermaid';
+import mermaid, { type MermaidConfigWithDefaults } from 'mermaid';
 import zenuml from '../../../../../mermaid-zenuml/dist/mermaid-zenuml.core.mjs';
 
 const init = mermaid.registerExternalDiagrams([zenuml]);
 
-export const render = async (id: string, code: string, config: MermaidConfig): Promise<string> => {
+export const render = async (
+  id: string,
+  code: string,
+  config: MermaidConfigWithDefaults
+): Promise<string> => {
   await init;
   mermaid.initialize(config);
   const { svg } = await mermaid.render(id, code);
diff --git a/packages/mermaid/src/mermaid.ts b/packages/mermaid/src/mermaid.ts
index 8194872d4..791ddd808 100644
--- a/packages/mermaid/src/mermaid.ts
+++ b/packages/mermaid/src/mermaid.ts
@@ -3,7 +3,7 @@
  * functionality and to render the diagrams to svg code!
  */
 import { dedent } from 'ts-dedent';
-import type { MermaidConfig } from './config.type.js';
+import type { MermaidConfigWithDefaults, MermaidConfig } from './config.type.js';
 import { log } from './logger.js';
 import utils from './utils.js';
 import type { ParseOptions, ParseResult, RenderResult } from './mermaidAPI.js';
@@ -18,6 +18,7 @@ import type { UnknownDiagramError } from './errors.js';
 import { addDiagrams } from './diagram-api/diagram-orchestration.js';
 
 export type {
+  MermaidConfigWithDefaults,
   MermaidConfig,
   DetailedError,
   ExternalDiagramDefinition,
@@ -330,8 +331,8 @@ const executeQueue = async () => {
  * // throws Error
  * ```
  */
-const parse: typeof mermaidAPI.parse = async (text, parseOptions) => {
-  return new Promise((resolve, reject) => {
+const parse = async (text: string, parseOptions?: ParseOptions & { suppressErrors: true }) => {
+  return new Promise<ParseResult | false>((resolve, reject) => {
     // This promise will resolve when the render call is done.
     // It will be queued first and will be executed when it is first in line
     const performCall = () =>
diff --git a/packages/mermaid/src/mermaidAPI.spec.ts b/packages/mermaid/src/mermaidAPI.spec.ts
index 849f8f026..a836fda7a 100644
--- a/packages/mermaid/src/mermaidAPI.spec.ts
+++ b/packages/mermaid/src/mermaidAPI.spec.ts
@@ -35,7 +35,7 @@ vi.mock('./diagrams/state/stateRenderer-v2.js');
 // -------------------------------------
 
 import assignWithDepth from './assignWithDepth.js';
-import type { MermaidConfig } from './config.type.js';
+import type { MermaidConfigWithDefaults } from './config.type.js';
 import mermaid from './mermaid.js';
 import mermaidAPI, {
   appendDivSvgG,
@@ -288,7 +288,7 @@ describe('mermaidAPI', () => {
       fontFamily: serif,
       altFontFamily: sansSerif,
       htmlLabels: true,
-    } as MermaidConfig;
+    } as MermaidConfigWithDefaults;
 
     it('gets the cssStyles from the theme', () => {
       const styles = createCssStyles(mocked_config_with_htmlLabels, null);
@@ -367,7 +367,7 @@ describe('mermaidAPI', () => {
         }
 
         // common suite and tests to verify that the right styles are created with the right htmlElements
-        function expect_correct_styles_with_htmlElements(mocked_config: MermaidConfig) {
+        function expect_correct_styles_with_htmlElements(mocked_config: MermaidConfigWithDefaults) {
           describe('creates styles for "> *" and  "span" elements', () => {
             const htmlElements = ['> *', 'span'];
 
@@ -396,7 +396,7 @@ describe('mermaidAPI', () => {
             flowchart: {
               htmlLabels: true,
             },
-          } as MermaidConfig;
+          } as MermaidConfigWithDefaults;
           expect_correct_styles_with_htmlElements(mocked_config_flowchart_htmlLabels);
         });
 
@@ -405,7 +405,7 @@ describe('mermaidAPI', () => {
             themeCSS: 'default',
             fontFamily: 'serif',
             altFontFamily: 'sans-serif',
-          } as MermaidConfig;
+          } as MermaidConfigWithDefaults;
 
           describe('creates styles for shape elements "rect", "polygon", "ellipse", and "circle"', () => {
             const htmlElements = ['rect', 'polygon', 'ellipse', 'circle'];
@@ -430,7 +430,7 @@ describe('mermaidAPI', () => {
       themeCSS: 'default',
       htmlLabels: true,
       themeVariables: { fontFamily: 'serif' },
-    } as MermaidConfig;
+    } as MermaidConfigWithDefaults;
 
     const classDef1 = { id: 'classDef1', styles: ['style1-1'], textStyles: [] };
 
diff --git a/packages/mermaid/src/mermaidAPI.ts b/packages/mermaid/src/mermaidAPI.ts
index 64508aa68..df79ed7f2 100644
--- a/packages/mermaid/src/mermaidAPI.ts
+++ b/packages/mermaid/src/mermaidAPI.ts
@@ -20,7 +20,7 @@ import { version } from '../package.json';
 import { Diagram } from './Diagram.js';
 import { addSVGa11yTitleDescription, setA11yDiagramInfo } from './accessibility.js';
 import * as configApi from './config.js';
-import type { MermaidConfig, PartialMermaidConfig } from './config.type.js';
+import type { MermaidConfigWithDefaults, MermaidConfig } from './config.type.js';
 import { addDiagrams } from './diagram-api/diagram-orchestration.js';
 import type { DiagramMetadata, DiagramStyleClassDef } from './diagram-api/types.js';
 import { evaluate } from './diagrams/common/common.js';
@@ -151,7 +151,7 @@ export const cssImportantStyles = (
  * @returns  the string with all the user styles
  */
 export const createCssStyles = (
-  config: MermaidConfig,
+  config: MermaidConfigWithDefaults,
   classDefs: Record<string, DiagramStyleClassDef> | null | undefined = {}
 ): string => {
   let cssStyles = '';
@@ -198,7 +198,7 @@ export const createCssStyles = (
 };
 
 export const createUserStyles = (
-  config: MermaidConfig,
+  config: MermaidConfigWithDefaults,
   graphType: string,
   classDefs: Record<string, DiagramStyleClassDef> | undefined,
   svgId: string
@@ -517,7 +517,7 @@ const render = async function (
 /**
  * @param  options - Initial Mermaid options
  */
-function initialize(options: PartialMermaidConfig = {}) {
+function initialize(options: MermaidConfig = {}) {
   // Handle legacy location of font-family configuration
   if (options?.fontFamily && !options.themeVariables?.fontFamily) {
     if (!options.themeVariables) {
diff --git a/packages/mermaid/src/preprocess.ts b/packages/mermaid/src/preprocess.ts
index e8504953b..c7cbc17c7 100644
--- a/packages/mermaid/src/preprocess.ts
+++ b/packages/mermaid/src/preprocess.ts
@@ -1,4 +1,4 @@
-import type { PartialMermaidConfig } from './config.type.js';
+import type { MermaidConfig } from './config.type.js';
 import { cleanupComments } from './diagram-api/comments.js';
 import { extractFrontMatter } from './diagram-api/frontmatter.js';
 import type { DiagramMetadata } from './diagram-api/types.js';
@@ -31,7 +31,7 @@ const processFrontmatter = (code: string) => {
 };
 
 const processDirectives = (code: string) => {
-  const initDirective: PartialMermaidConfig = utils.detectInit(code) ?? {};
+  const initDirective: MermaidConfig = utils.detectInit(code) ?? {};
   const wrapDirectives = utils.detectDirective(code, 'wrap');
   if (Array.isArray(wrapDirectives)) {
     initDirective.wrap = wrapDirectives.some(({ type }) => {
diff --git a/packages/mermaid/src/rendering-util/createText.ts b/packages/mermaid/src/rendering-util/createText.ts
index 0a7e3bbb0..3697d6e40 100644
--- a/packages/mermaid/src/rendering-util/createText.ts
+++ b/packages/mermaid/src/rendering-util/createText.ts
@@ -1,6 +1,6 @@
 /* eslint-disable @typescript-eslint/no-explicit-any */
 // @ts-nocheck TODO: Fix types
-import type { MermaidConfig } from '../config.type.js';
+import type { MermaidConfigWithDefaults } from '../config.type.js';
 import type { Group } from '../diagram-api/types.js';
 import type { D3TSpanElement, D3TextElement } from '../diagrams/common/commonTypes.js';
 import { log } from '../logger.js';
@@ -195,7 +195,7 @@ export const createText = (
     width = 200,
     addSvgBackground = false,
   } = {},
-  config: MermaidConfig
+  config: MermaidConfigWithDefaults
 ) => {
   log.info('createText', text, style, isTitle, classes, useHtmlLabels, isNode, addSvgBackground);
   if (useHtmlLabels) {
diff --git a/packages/mermaid/src/rendering-util/handle-markdown-text.ts b/packages/mermaid/src/rendering-util/handle-markdown-text.ts
index 4b20e368d..f5cf0f69d 100644
--- a/packages/mermaid/src/rendering-util/handle-markdown-text.ts
+++ b/packages/mermaid/src/rendering-util/handle-markdown-text.ts
@@ -1,14 +1,16 @@
-import type { Content } from 'mdast';
 import { fromMarkdown } from 'mdast-util-from-markdown';
 import { dedent } from 'ts-dedent';
-import type { PartialMermaidConfig } from '../config.type.js';
+import type { MermaidConfigWithDefaults } from '../config.type.js';
 import type { MarkdownLine, MarkdownWordType } from './types.js';
+import { RootContent } from 'mdast';
+
+type MarkdownConfig = Partial<Pick<MermaidConfigWithDefaults, 'markdownAutoWrap'>>;
 
 /**
  * @param markdown - markdown to process
  * @returns processed markdown
  */
-function preprocessMarkdown(markdown: string, { markdownAutoWrap }: PartialMermaidConfig): string {
+function preprocessMarkdown(markdown: string, { markdownAutoWrap }: MarkdownConfig): string {
   // Replace multiple newlines with a single newline
   const withoutMultipleNewlines = markdown.replace(/\n{2,}/g, '\n');
   // Remove extra spaces at the beginning of each line
@@ -22,16 +24,13 @@ function preprocessMarkdown(markdown: string, { markdownAutoWrap }: PartialMerma
 /**
  * @param markdown - markdown to split into lines
  */
-export function markdownToLines(
-  markdown: string,
-  config: PartialMermaidConfig = {}
-): MarkdownLine[] {
+export function markdownToLines(markdown: string, config: MarkdownConfig = {}): MarkdownLine[] {
   const preprocessedMarkdown = preprocessMarkdown(markdown, config);
   const { children } = fromMarkdown(preprocessedMarkdown);
   const lines: MarkdownLine[] = [[]];
   let currentLine = 0;
 
-  function processNode(node: Content, parentType: MarkdownWordType = 'normal') {
+  function processNode(node: RootContent, parentType: MarkdownWordType = 'normal') {
     if (node.type === 'text') {
       const textLines = node.value.split('\n');
       textLines.forEach((textLine, index) => {
@@ -63,10 +62,10 @@ export function markdownToLines(
   return lines;
 }
 
-export function markdownToHTML(markdown: string, { markdownAutoWrap }: PartialMermaidConfig = {}) {
+export function markdownToHTML(markdown: string, { markdownAutoWrap }: MarkdownConfig = {}) {
   const { children } = fromMarkdown(markdown);
 
-  function output(node: Content): string {
+  function output(node: RootContent): string {
     if (node.type === 'text') {
       if (markdownAutoWrap === false) {
         return node.value.replace(/\n/g, '<br/>').replace(/ /g, '&nbsp;');
diff --git a/packages/mermaid/src/schemas/config.schema.yaml b/packages/mermaid/src/schemas/config.schema.yaml
index 8af9e6314..2a89d4d0b 100644
--- a/packages/mermaid/src/schemas/config.schema.yaml
+++ b/packages/mermaid/src/schemas/config.schema.yaml
@@ -1,11 +1,11 @@
 # Used for VS Code's YAML plugin to automatically error on invalid types
 # yaml-language-server: $schema=https://json-schema.org/draft/2019-09/schema
 
-# This file defines the MermaidConfig JSON Schema as a YAML file.
+# This file defines the MermaidConfigWithDefaults JSON Schema as a YAML file.
 #
 # From this file, the following things can be generated:
 #   - `scripts/create-types-from-json-schema.mjs`
-#     Used to generate the `src/config.type.ts` TypeScript types for MermaidConfig
+#     Used to generate the `src/config.type.ts` TypeScript types for MermaidConfigWithDefaults
 #     with the `json-schema-to-typescript` NPM package.
 #   - `.build/jsonSchema.ts`
 #     Used to generate the default values from the `default` keys in this
@@ -20,13 +20,13 @@
 # - Use the `|` character for multi-line strings
 # - Use `meta:enum` to document enum values (from jsonschema2md)
 # - Use `tsType` to override the TypeScript type (from json-schema-to-typescript)
-# - If adding a new object to `MermaidConfig` (e.g. a new diagram type),
+# - If adding a new object to `MermaidConfigWithDefaults` (e.g. a new diagram type),
 #   you may need to add it to `.build/jsonSchema.ts`, `src/docs.mts`
 #   and `scripts/create-types-from-json-schema.mjs`
 #   to get the default values/docs/types to generate properly.
 $id: https://mermaid.js.org/schemas/config.schema.json
 $schema: https://json-schema.org/draft/2019-09/schema
-title: Mermaid Config
+title: MermaidConfigWithDefaults
 type: object
 additionalProperties: false
 required:
@@ -261,11 +261,11 @@ properties:
       This is useful when you want to control how to handle syntax errors in your application.
 
 $defs: # JSON Schema definition (maybe we should move these to a separate file)
-  PartialMermaidConfig:
-    title: PartialMermaidConfig
-    description: MermaidConfig with all fields optional
+  MermaidConfig:
+    title: MermaidConfig
+    description: MermaidConfigWithDefaults with all fields optional
     type: object
-    tsType: "import('type-fest').PartialDeep<MermaidConfig>"
+    tsType: "import('type-fest').PartialDeep<MermaidConfigWithDefaults>"
   BaseDiagramConfig:
     # TODO: More config needs to be moved here
     title: Base Diagram Config
diff --git a/packages/mermaid/src/utils.ts b/packages/mermaid/src/utils.ts
index c05706714..fd1132eba 100644
--- a/packages/mermaid/src/utils.ts
+++ b/packages/mermaid/src/utils.ts
@@ -26,7 +26,7 @@ import {
 import memoize from 'lodash-es/memoize.js';
 import merge from 'lodash-es/merge.js';
 import assignWithDepth from './assignWithDepth.js';
-import type { MermaidConfig, PartialMermaidConfig } from './config.type.js';
+import type { MermaidConfigWithDefaults, MermaidConfig } from './config.type.js';
 import { detectType } from './diagram-api/detectType.js';
 import { directiveRegex } from './diagram-api/regexes.js';
 import common from './diagrams/common/common.js';
@@ -97,16 +97,16 @@ const directiveWithoutOpen =
  * @param config - Optional mermaid configuration object.
  * @returns The json object representing the init passed to mermaid.initialize()
  */
-export const detectInit = function (text: string): PartialMermaidConfig | undefined {
+export const detectInit = function (text: string): MermaidConfig | undefined {
   const inits = detectDirective(text, /(?:init\b)|(?:initialize\b)/);
-  let results: PartialMermaidConfig & { config?: unknown } = {};
+  let results: MermaidConfig & { config?: unknown } = {};
 
   if (Array.isArray(inits)) {
     const args = inits.map((init) => init.args);
     sanitizeDirective(args);
     results = assignWithDepth(results, [...args]);
   } else {
-    results = inits.args as PartialMermaidConfig;
+    results = inits.args as MermaidConfig;
   }
 
   if (!results) {
@@ -121,7 +121,7 @@ export const detectInit = function (text: string): PartialMermaidConfig | undefi
     if (type === 'flowchart-v2') {
       type = 'flowchart';
     }
-    results[type as keyof MermaidConfig] = results[prop];
+    results[type as keyof MermaidConfigWithDefaults] = results[prop];
     delete results[prop];
   }
 
@@ -249,7 +249,7 @@ export function interpolateToCurve(
  */
 export function formatUrl(
   linkStr: string,
-  config: Pick<MermaidConfig, 'securityLevel'>
+  config: Pick<MermaidConfigWithDefaults, 'securityLevel'>
 ): string | undefined {
   const url = linkStr.trim();