diff --git a/lib/ace/document.js b/lib/ace/document.js
index 6b792a5b..bd4454dc 100644
--- a/lib/ace/document.js
+++ b/lib/ace/document.js
@@ -56,7 +56,7 @@ var Document = function(text, mode) {
         this.setMode(mode);
     }
     
-    if (lang.isArray(text)) {
+    if (Array.isArray(text)) {
         this.$insertLines(0, text);
     } else {
         this.$insert({row: 0, column: 0}, text);
diff --git a/plugins/pilot/lang.js b/plugins/pilot/lang.js
index 49ba8763..2641837b 100644
--- a/plugins/pilot/lang.js
+++ b/plugins/pilot/lang.js
@@ -61,10 +61,6 @@ else {
     };
 }
 
-exports.isArray = function(value) {
-    return Object.prototype.toString.call(value) == "[object Array]";
-};
-
 exports.copyObject = function(obj) {
     var copy = {};
     for (var key in obj) {