diff --git a/.changeset/warm-coins-refuse.md b/.changeset/warm-coins-refuse.md
new file mode 100644
index 00000000000..6949b4ddb2f
--- /dev/null
+++ b/.changeset/warm-coins-refuse.md
@@ -0,0 +1,5 @@
+---
+'@astrojs/starlight': patch
+---
+
+Fixes colour contrast correction in code blocks
diff --git a/packages/starlight/integrations/expressive-code/theming.ts b/packages/starlight/integrations/expressive-code/theming.ts
index 39f96b1737f..e207aac3895 100644
--- a/packages/starlight/integrations/expressive-code/theming.ts
+++ b/packages/starlight/integrations/expressive-code/theming.ts
@@ -79,6 +79,7 @@ export function applyStarlightUiThemeColors(theme: ExpressiveCodeTheme) {
 
 	// Set theme `bg` color property for contrast calculations
 	theme.bg = isDark ? '#23262f' : '#f6f7f9';
+	theme.colors['editor.background'] = theme.bg;
 	// Set actual background color to the appropriate Starlight CSS variable
 	const editorBackgroundColor = isDark ? 'var(--sl-color-gray-6)' : 'var(--sl-color-gray-7)';