diff --git a/src/CallBlock.tsx b/src/CallBlock.tsx
index 2f7e75c..5ddd789 100644
--- a/src/CallBlock.tsx
+++ b/src/CallBlock.tsx
@@ -72,7 +72,7 @@ export function CallBlock({ state, setState }: CallBlockProps) {
 
 function filterFnInputs(fn: ResolvedType, input: ResolvedType) {
   const resolved = evalCallBlock(fn, input);
-  return (resolved && !(resolved instanceof Error));
+  return (resolved && !(resolved instanceof DeepError));
 }
 
 function FunctionHeader({ fn, setFn, input, onFnCancel }) {