diff --git a/types/index.d.ts b/types/index.d.ts
index e49da3f..8a02ef0 100755
--- a/types/index.d.ts
+++ b/types/index.d.ts
@@ -33,7 +33,7 @@ export default function transformer(
     compilerOptions?: ts.CompilerOptions;
     fileNames?: string[];
   }
-): ts.CustomTransformer
+): ts.CustomTransformerFactory
 
 
 /* ****************************************************************************************************************** *