diff --git a/lib/babel/generation/generators/expressions.js b/lib/babel/generation/generators/expressions.js
index cb5a49d253..68b54ed368 100644
--- a/lib/babel/generation/generators/expressions.js
+++ b/lib/babel/generation/generators/expressions.js
@@ -1,8 +1,8 @@
 "use strict";
 
-var util     = require("../../util");
-var t        = require("../../types");
-var isNumber = require("lodash/lang/isNumber");
+var isInteger = require("is-integer");
+var isNumber  = require("lodash/lang/isNumber");
+var t         = require("../../types");
 
 exports.UnaryExpression = function (node, print) {
   var hasSpace = /[a-z]$/.test(node.operator);
@@ -146,7 +146,7 @@ exports.MemberExpression = function (node, print) {
     this.push("]");
   } else {
     // 5..toFixed(2);
-    if (t.isLiteral(obj) && util.isInteger(obj.value) && !SCIENTIFIC_NOTATION.test(obj.value.toString())) {
+    if (t.isLiteral(obj) && isInteger(obj.value) && !SCIENTIFIC_NOTATION.test(obj.value.toString())) {
       this.push(".");
     }
 
diff --git a/lib/babel/util.js b/lib/babel/util.js
index 861d6b1b32..865192aea7 100644
--- a/lib/babel/util.js
+++ b/lib/babel/util.js
@@ -5,7 +5,6 @@ require("./patch");
 var cloneDeep  = require("lodash/lang/cloneDeep");
 var contains   = require("lodash/collection/contains");
 var traverse   = require("./traversal");
-var isNumber   = require("lodash/lang/isNumber");
 var isString   = require("lodash/lang/isString");
 var isRegExp   = require("lodash/lang/isRegExp");
 var isEmpty    = require("lodash/lang/isEmpty");
@@ -34,10 +33,6 @@ exports.normalisePathSeparator = function (filename) {
   return filename.replace(/\\/g, "/");
 };
 
-exports.isInteger = function (i) {
-  return isNumber(i) && i % 1 === 0;
-};
-
 exports.resolve = function (loc) {
   try {
     return require.resolve(loc);
diff --git a/package.json b/package.json
index 7db66f2148..b5580293a1 100644
--- a/package.json
+++ b/package.json
@@ -50,6 +50,7 @@
     "esutils": "^1.1.6",
     "fs-readdir-recursive": "^0.1.0",
     "globals": "^6.2.0",
+    "is-integer": "^1.0.4",
     "js-tokenizer": "^1.3.3",
     "leven": "^1.0.1",
     "lodash": "^3.2.0",