diff --git a/lib/deap.js b/lib/deap.js
index 386eb92..db22d53 100755
--- a/lib/deap.js
+++ b/lib/deap.js
@@ -26,7 +26,7 @@ function clone(val) {
 
 function extend(a, b /*, [b2..n] */) {
 	slice.call(arguments, 1).forEach(function(b) {
-		Object.getOwnPropertyNames(b).forEach(function(p) {
+		Object.keys(b).forEach(function(p) {
 			a[p] = b[p];
 		});
 	});
@@ -35,7 +35,7 @@ function extend(a, b /*, [b2..n] */) {
 
 function deepExtend(a, b /*, [b2..n] */) {
 	slice.call(arguments, 1).forEach(function(b) {
-		Object.getOwnPropertyNames(b).forEach(function(p) {
+		Object.keys(b).forEach(function(p) {
 			if(typeOf(b[p]) === 'object' && typeOf(a[p]) === 'object')
 				deepExtend(a[p], b[p]);
 			else
@@ -47,7 +47,7 @@ function deepExtend(a, b /*, [b2..n] */) {
 
 function merge(a, b /*, [b2..n] */) {
 	slice.call(arguments, 1).forEach(function(b) {
-		Object.getOwnPropertyNames(b).forEach(function(p) {
+		Object.keys(b).forEach(function(p) {
 			if(a.hasOwnProperty(p)) a[p] = b[p];
 		});
 	});
@@ -57,7 +57,7 @@ function merge(a, b /*, [b2..n] */) {
 function deepMerge(a, b /*, [b2..n] */) {
 	slice.call(arguments, 1).forEach(function(b) {
 		var ap, bp, ta, tb;
-		Object.getOwnPropertyNames(b).forEach(function(p) {
+		Object.keys(b).forEach(function(p) {
 			if(a.hasOwnProperty(p)) {
 				ap = a[p];
 				bp = b[p];
diff --git a/test/extend.test.js b/test/extend.test.js
index abc64d4..aeeb9de 100755
--- a/test/extend.test.js
+++ b/test/extend.test.js
@@ -80,6 +80,14 @@ describe('shallow extend', function() {
 
 		assert.strictEqual(result.array, array);
 	});
+
+	it('should not pick up non-enumberable properties', function() {
+		var result = shallow({}, function() {});
+
+		assert.deepEqual(result, {});
+		assert.equal(Object.keys(result).length, 0);
+		assert.equal(Object.getOwnPropertyNames(result).length, 0);
+	});
 });
 
 describe('deep extend', function() {