diff --git a/src/scripts/app.ts b/src/scripts/app.ts
index 438dd1861..686dc5926 100644
--- a/src/scripts/app.ts
+++ b/src/scripts/app.ts
@@ -381,7 +381,7 @@ export class ComfyApp {
                 // @ts-expect-error
                 prop.value = value
                 // @ts-expect-error
-                prop.callback(value)
+                prop.callback?.(value)
               }
             }
           })