diff --git a/packages/babel-parser/src/parser/node.js b/packages/babel-parser/src/parser/node.js
index 5ed447018d..ea04076bf3 100644
--- a/packages/babel-parser/src/parser/node.js
+++ b/packages/babel-parser/src/parser/node.js
@@ -29,8 +29,10 @@ class Node implements NodeBase {
 
   __clone(): this {
     // $FlowIgnore
-    const node2: any = new Node();
-    Object.keys(this).forEach(key => {
+    const newNode: any = new Node();
+    const keys = Object.keys(this);
+    for (let i = 0, length = keys.length; i < length; i++) {
+      const key = keys[i];
       // Do not clone comments that are already attached to the node
       if (
         key !== "leadingComments" &&
@@ -38,11 +40,11 @@ class Node implements NodeBase {
         key !== "innerComments"
       ) {
         // $FlowIgnore
-        node2[key] = this[key];
+        newNode[key] = this[key];
       }
-    });
+    }
 
-    return node2;
+    return newNode;
   }
 }
 
diff --git a/packages/babel-parser/src/tokenizer/state.js b/packages/babel-parser/src/tokenizer/state.js
index 794bc32014..9bc2b81c02 100644
--- a/packages/babel-parser/src/tokenizer/state.js
+++ b/packages/babel-parser/src/tokenizer/state.js
@@ -178,7 +178,9 @@ export default class State {
 
   clone(skipArrays?: boolean): State {
     const state = new State();
-    Object.keys(this).forEach(key => {
+    const keys = Object.keys(this);
+    for (let i = 0, length = keys.length; i < length; i++) {
+      const key = keys[i];
       // $FlowIgnore
       let val = this[key];
 
@@ -188,7 +190,8 @@ export default class State {
 
       // $FlowIgnore
       state[key] = val;
-    });
+    }
+
     return state;
   }
 }