diff --git a/frontend/src/lib/components/InputTransformForm.svelte b/frontend/src/lib/components/InputTransformForm.svelte
index 52ea222c6a..b72c11d3f5 100644
--- a/frontend/src/lib/components/InputTransformForm.svelte
+++ b/frontend/src/lib/components/InputTransformForm.svelte
@@ -51,7 +51,7 @@
 		propertyType = arg.type
 	}
 
-	$: arg?.type !== propertyType && updatePropertyType()
+	$: arg?.type && arg.type !== propertyType && updatePropertyType()
 
 	function getPropertyType(arg: InputTransform | any): 'static' | 'javascript' {
 		let type: 'static' | 'javascript' = arg?.type ?? 'static'