diff --git a/packages/core/global-types.d.ts b/packages/core/global-types.d.ts
index fa03c4782..1272d24e0 100644
--- a/packages/core/global-types.d.ts
+++ b/packages/core/global-types.d.ts
@@ -128,7 +128,7 @@ declare namespace NodeJS {
 		rootLayout: any;
 	}
 }
-declare const __DEV__: string;
+declare const __DEV__: boolean;
 declare const __CSS_PARSER__: string;
 declare const __NS_WEBPACK__: boolean;
 declare const __UI_USE_EXTERNAL_RENDERER__: boolean;