diff --git a/packages/exo/test/test-heap-classes.js b/packages/exo/test/test-heap-classes.js
index 77b031a270..d41352e986 100644
--- a/packages/exo/test/test-heap-classes.js
+++ b/packages/exo/test/test-heap-classes.js
@@ -180,12 +180,13 @@ test('missing interface', t => {
   );
   const greeterMaker = makeExo('greeterMaker', undefined, {
     makeSayHello() {
-      return () => 'hello';
+      const helloFunc = () => 'hello';
+      return harden(helloFunc);
     },
   });
   t.throws(() => greeterMaker.makeSayHello(), {
     message:
-      'In "makeSayHello" method of (greeterMaker): result: "[Symbol(passStyle)]" property expected: "[Function <anon>]"',
+      'In "makeSayHello" method of (greeterMaker): result: Remotables must be explicitly declared: "[Function helloFunc]"',
   });
   t.is(greeterMaker[GET_INTERFACE_GUARD]?.(), undefined);
 });
diff --git a/packages/pass-style/src/remotable.js b/packages/pass-style/src/remotable.js
index 788ae19d12..d4c17986fa 100644
--- a/packages/pass-style/src/remotable.js
+++ b/packages/pass-style/src/remotable.js
@@ -87,7 +87,11 @@ const checkRemotableProtoOf = (original, check) => {
   //        }}
   //
   const proto = getPrototypeOf(original);
-  if (proto === objectPrototype || proto === null) {
+  if (
+    proto === objectPrototype ||
+    proto === null ||
+    proto === Function.prototype
+  ) {
     return (
       reject && reject`Remotables must be explicitly declared: ${q(original)}`
     );