diff --git a/modernizr/modernizr.d.ts b/modernizr/modernizr.d.ts
index 5827bbf9eb..a9104fd226 100644
--- a/modernizr/modernizr.d.ts
+++ b/modernizr/modernizr.d.ts
@@ -96,9 +96,8 @@ interface ModernizrStatic {
     load(resourceObject: any): void;
     load(resourceString: string): void;
 
-    prefixed(): boolean;
-    prefixed(property: string): boolean;
-    prefixed(property: string, obj: any, element?: any): boolean;
+    prefixed(property: string): any;
+    prefixed(property: string, obj: any, element?: any): any;
 
     mq(mediaQuery: string): boolean;