diff --git a/packages/rrweb/src/utils.ts b/packages/rrweb/src/utils.ts
index 782fd3dd8e..106097bf5e 100644
--- a/packages/rrweb/src/utils.ts
+++ b/packages/rrweb/src/utils.ts
@@ -163,6 +163,9 @@ export function patch(
     // Make sure it's a function first, as we need to attach an empty prototype for `defineProperties` to work
     // otherwise it'll throw "TypeError: Object.defineProperties called on non-object"
     if (typeof wrapped === 'function') {
+      wrapped.toString = function() {
+        return original.toString();
+      };
       // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
       wrapped.prototype = wrapped.prototype || {};
       Object.defineProperties(wrapped, {