diff --git a/distribution/changelog.txt b/distribution/changelog.txt
index f6f4be745f..d66f9063df 100644
--- a/distribution/changelog.txt
+++ b/distribution/changelog.txt
@@ -14,6 +14,7 @@
 - Fix: [#20262] Title screen music missing when “random” title music is selected and RCT1 is no longer linked.
 - Fix: [#20361] Crash when using random map generation.
 - Fix: [#20413] Crash when attempting to navigate an empty console history.
+- Fix: [#20417] Plugin/custom windows are missing the left border in the title bar.
 
 0.4.5 (2023-05-08)
 ------------------------------------------------------------------------
diff --git a/src/openrct2-ui/scripting/CustomWindow.cpp b/src/openrct2-ui/scripting/CustomWindow.cpp
index 926e93dd69..9e3f78b58b 100644
--- a/src/openrct2-ui/scripting/CustomWindow.cpp
+++ b/src/openrct2-ui/scripting/CustomWindow.cpp
@@ -48,10 +48,8 @@ namespace OpenRCT2::Ui::Windows
     };
 
     static Widget CustomDefaultWidgets[] = {
-        { WindowWidgetType::Frame, 0, 0, 0, 0, 0, 0xFFFFFFFF, STR_NONE },                  // panel / background
-        { WindowWidgetType::Caption, 0, 0, 0, 1, 14, STR_STRING, STR_WINDOW_TITLE_TIP },   // title bar
-        { WindowWidgetType::CloseBox, 0, 0, 0, 2, 13, STR_CLOSE_X, STR_CLOSE_WINDOW_TIP }, // close x button
-        { WindowWidgetType::Resize, 1, 0, 0, 14, 0, 0xFFFFFFFF, STR_NONE },                // content panel
+        WINDOW_SHIM(STR_STRING, 50, 50),
+        MakeWidget({ 0, 14 }, { 50, 36 }, WindowWidgetType::Resize, WindowColour::Secondary), // content panel
     };
 
     struct CustomWidgetDesc