diff --git a/src/sandbox/common.ts b/src/sandbox/common.ts
index e05700c..909198c 100644
--- a/src/sandbox/common.ts
+++ b/src/sandbox/common.ts
@@ -27,7 +27,12 @@ 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]));
+    // use for..in rather than Object.keys.forEach for performance reason
+    // eslint-disable-next-line guard-for-in,no-restricted-syntax
+    for (const key in value) {
+      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 });
@@ -37,7 +42,7 @@ export function getTargetValue(target: any, value: any): any {
   return value;
 }
 
-const getterInvocationResultMap = new Map<CallableFunction, any>();
+const getterInvocationResultMap = new WeakMap<CallableFunction, any>();
 
 export function getProxyPropertyValue(getter: CallableFunction) {
   const getterResult = getterInvocationResultMap.get(getter);
diff --git a/src/sandbox/patchers/dynamicAppend.ts b/src/sandbox/patchers/dynamicAppend.ts
index c601359..7e28e63 100644
--- a/src/sandbox/patchers/dynamicAppend.ts
+++ b/src/sandbox/patchers/dynamicAppend.ts
@@ -33,7 +33,7 @@ const SCRIPT_TAG_NAME = 'SCRIPT';
 const LINK_TAG_NAME = 'LINK';
 const STYLE_TAG_NAME = 'STYLE';
 
-const proxyContainerInfoMapper = new Map<WindowProxy, Record<string, any>>();
+const proxyContainerInfoMapper = new WeakMap<WindowProxy, Record<string, any>>();
 
 function isHijackingTag(tagName?: string) {
   return (
diff --git a/src/utils.ts b/src/utils.ts
index 0e7867e..91603bc 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -22,16 +22,22 @@ export function nextTick(cb: () => void): void {
   Promise.resolve().then(cb);
 }
 
-export function isConstructable(fn: () => void | FunctionConstructor) {
+const constructableMap = new WeakMap<Function, boolean>();
+export function isConstructable(fn: () => any | FunctionConstructor) {
+  if (constructableMap.has(fn)) {
+    return constructableMap.get(fn);
+  }
+
   const constructableFunctionRegex = /^function\b\s[A-Z].*/;
   const classRegex = /^class\b/;
 
   // 有 prototype 并且 prototype 上有定义一系列非 constructor 属性，则可以认为是一个构造函数
-  return (
+  const constructable =
     (fn.prototype && fn.prototype.constructor === fn && Object.getOwnPropertyNames(fn.prototype).length > 1) ||
     constructableFunctionRegex.test(fn.toString()) ||
-    classRegex.test(fn.toString())
-  );
+    classRegex.test(fn.toString());
+  constructableMap.set(fn, constructable);
+  return constructable;
 }
 
 /**
@@ -45,12 +51,18 @@ export const isCallable = naughtySafari
   ? (fn: any) => typeof fn === 'function' && typeof fn !== 'undefined'
   : (fn: any) => typeof fn === 'function';
 
+const boundedMap = new WeakMap<CallableFunction, boolean>();
 export function isBoundedFunction(fn: CallableFunction) {
+  if (boundedMap.has(fn)) {
+    return boundedMap.get(fn);
+  }
   /*
    indexOf is faster than startsWith
    see https://jsperf.com/string-startswith/72
    */
-  return fn.name.indexOf('bound ') === 0 && !fn.hasOwnProperty('prototype');
+  const bounded = fn.name.indexOf('bound ') === 0 && !fn.hasOwnProperty('prototype');
+  boundedMap.set(fn, bounded);
+  return bounded;
 }
 
 /**