diff --git a/lib.rs b/lib.rs
index 589a0a6..58220d7 100644
--- a/lib.rs
+++ b/lib.rs
@@ -111,6 +111,9 @@ pub fn element(_args: TokenStream, input: TokenStream) -> TokenStream {
                     }
                 }
             }
+            fn type_id(&self) -> TypeId {
+                TypeId::of::<Button>()
+            }
         }
     };