diff --git a/packages/core/application/application-common.ts b/packages/core/application/application-common.ts
index 30412a3f5..9b0a702b6 100644
--- a/packages/core/application/application-common.ts
+++ b/packages/core/application/application-common.ts
@@ -97,11 +97,6 @@ interface ApplicationEvents {
 	 */
 	on(event: 'livesync', callback: (args: ApplicationEventData) => void, thisArg?: any): void;
 
-	/**
-	 * This event is raised when application css is changed.
-	 */
-	on(event: 'cssChanged', callback: (args: CssChangedEventData) => void, thisArg?: any): void;
-
 	/**
 	 * This event is raised on application launchEvent.
 	 */