diff --git a/src/sandbox/common.ts b/src/sandbox/common.ts
index af34633..e05700c 100644
--- a/src/sandbox/common.ts
+++ b/src/sandbox/common.ts
@@ -28,6 +28,8 @@ export function getTargetValue(target: any, value: any): any {
     const boundValue = value.bind(target);
     // some callable function has custom fields, we need to copy the enumerable props to boundValue. such as moment function.
     Object.keys(value).forEach(key => (boundValue[key] = value[key]));
+    // copy prototype, for performance reason, we use in operator to check rather than hasOwnProperty
+    if ('prototype' in value) boundValue.prototype = value.prototype;
     Object.defineProperty(value, boundValueSymbol, { enumerable: false, value: boundValue });
     return boundValue;
   }