diff --git a/jquery.gridster/gridster.d.ts b/jquery.gridster/gridster.d.ts
index 6019ebb067..968c0f3330 100644
--- a/jquery.gridster/gridster.d.ts
+++ b/jquery.gridster/gridster.d.ts
@@ -138,7 +138,7 @@ interface GridsterOptions {
 	/**
 	* Return the data you want for each widget in the serialization.
 	**/
-	serialize_params?: <T>($w: JQuery, wgd: GridsterCoords) => T;
+	serialize_params?: ($w: JQuery, wgd: GridsterCoords) => any;
 
 	/**
 	* An object with all options for Collision class you want to overwrite.  @see GridsterCollision or docs for more info.