diff --git a/lib/ace/ace.js b/lib/ace/ace.js
index 500b458f..6c8a6126 100644
--- a/lib/ace/ace.js
+++ b/lib/ace/ace.js
@@ -107,6 +107,7 @@ exports.edit = function(el) {
     event.addListener(window, "resize", env.onResize);
     editor.on("destroy", function() {
         event.removeListener(window, "resize", env.onResize);
+        env.editor.container.env = null; // prevent memory leak on old ie
     });
     editor.container.env = editor.env = env;
     return editor;
diff --git a/lib/ace/edit_session.js b/lib/ace/edit_session.js
index 73a184fd..f563579d 100644
--- a/lib/ace/edit_session.js
+++ b/lib/ace/edit_session.js
@@ -966,17 +966,13 @@ var EditSession = function(text, mode) {
     };
 
     this.$startWorker = function() {
-        if (typeof Worker !== "undefined" && !require.noWorker) {
-            try {
-                this.$worker = this.$mode.createWorker(this);
-            } catch (e) {
-                console.log("Could not load worker");
-                console.log(e);
-                this.$worker = null;
-            }
-        }
-        else
+        try {
+            this.$worker = this.$mode.createWorker(this);
+        } catch (e) {
+            console.log("Could not load worker");
+            console.log(e);
             this.$worker = null;
+        }
     };
 
     /**