diff --git a/library/include/DataIdentity.h b/library/include/DataIdentity.h
index 4f275b854..ff15535d1 100644
--- a/library/include/DataIdentity.h
+++ b/library/include/DataIdentity.h
@@ -40,7 +40,7 @@ namespace std {
 };
 
 namespace df {
-    class widget;
+    struct widget;
 }
 
 /*