diff --git a/.dorpsgek.yml b/.dorpsgek.yml
index bbd2b9780a..2a1dc5f0f5 100644
--- a/.dorpsgek.yml
+++ b/.dorpsgek.yml
@@ -17,3 +17,4 @@ notifications:
   workflow-run:
     only:
     - .github/workflows/release.yml
+    - .github/workflows/ci-nightly.yml
diff --git a/.github/workflows/ci-build.yml b/.github/workflows/ci-build.yml
index 059ee338ab..0cedad4c61 100644
--- a/.github/workflows/ci-build.yml
+++ b/.github/workflows/ci-build.yml
@@ -1,4 +1,4 @@
-name: CI
+name: CI - Build
 
 on:
   pull_request:
@@ -38,10 +38,6 @@ jobs:
           compiler: gcc
           cxxcompiler: g++
           libraries: libsdl2-dev
-        - name: GCC - SDL1.2
-          compiler: gcc
-          cxxcompiler: g++
-          libraries: libsdl1.2-dev
         - name: GCC - Dedicated
           compiler: gcc
           cxxcompiler: g++
@@ -83,13 +79,11 @@ jobs:
       matrix:
         include:
         - os: windows-latest
-          name: Windows
           arch: x86
         - os: windows-latest
-          name: Windows
           arch: x64
 
-    name: ${{ matrix.name }} (${{ matrix.arch }})
+    name: Windows (${{ matrix.arch }})
 
     uses: ./.github/workflows/ci-windows.yml
     secrets: inherit
@@ -98,25 +92,6 @@ jobs:
       os: ${{ matrix.os }}
       arch: ${{ matrix.arch }}
 
-  mingw:
-    strategy:
-      fail-fast: false
-      matrix:
-        include:
-          - msystem: MINGW64
-            arch: x86_64
-          - msystem: MINGW32
-            arch: i686
-
-    name: MinGW (${{ matrix.arch }})
-
-    uses: ./.github/workflows/ci-mingw.yml
-    secrets: inherit
-
-    with:
-      msystem: ${{ matrix.msystem }}
-      arch: ${{ matrix.arch }}
-
   check_annotations:
     name: Check Annotations
     needs:
@@ -124,7 +99,6 @@ jobs:
     - linux
     - macos
     - windows
-    - mingw
 
     if: always() && github.event_name == 'pull_request'
 
diff --git a/.github/workflows/ci-nightly.yml b/.github/workflows/ci-nightly.yml
new file mode 100644
index 0000000000..15bc55a97c
--- /dev/null
+++ b/.github/workflows/ci-nightly.yml
@@ -0,0 +1,82 @@
+name: CI - Nightly
+
+on:
+  schedule:
+  - cron: '0 3 * * *'
+  workflow_dispatch:
+
+env:
+  CTEST_OUTPUT_ON_FAILURE: 1
+
+jobs:
+  linux:
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+        - name: GCC - SDL1.2
+          compiler: gcc
+          cxxcompiler: g++
+          libraries: libsdl1.2-dev
+
+    name: Linux (${{ matrix.name }})
+
+    uses: ./.github/workflows/ci-linux.yml
+    secrets: inherit
+
+    with:
+      compiler: ${{ matrix.compiler }}
+      cxxcompiler: ${{ matrix.cxxcompiler }}
+      libraries: ${{ matrix.libraries }}
+      extra-cmake-parameters:
+
+  macos:
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+        - arch: x64
+          full_arch: x86_64
+
+    name: Mac OS (${{ matrix.arch }})
+
+    uses: ./.github/workflows/ci-macos.yml
+    secrets: inherit
+
+    with:
+      arch: ${{ matrix.arch }}
+      full_arch: ${{ matrix.full_arch }}
+
+  mingw:
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+        - msystem: MINGW64
+          arch: x86_64
+        - msystem: MINGW32
+          arch: i686
+
+    name: MinGW (${{ matrix.arch }})
+
+    uses: ./.github/workflows/ci-mingw.yml
+    secrets: inherit
+
+    with:
+      msystem: ${{ matrix.msystem }}
+      arch: ${{ matrix.arch }}
+
+  check_annotations:
+    name: Check Annotations
+    needs:
+    - linux
+    - macos
+    - mingw
+
+    if: always()
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Check annotations
+      uses: OpenTTD/actions/annotation-check@v5