diff --git a/lib/ace/keyboard/textinput.js b/lib/ace/keyboard/textinput.js
index f0830e71..a3c7f38d 100644
--- a/lib/ace/keyboard/textinput.js
+++ b/lib/ace/keyboard/textinput.js
@@ -394,6 +394,7 @@ var TextInput = function(parentNode, host) {
         var c = inComposition;
         inComposition = false;
         var timer = setTimeout(function() {
+            timer = null;
             var str = text.value.replace(/\x01/g, "");
             // console.log(str, c.lastValue)
             if (inComposition)
@@ -407,14 +408,15 @@ var TextInput = function(parentNode, host) {
         });
         inputHandler = function compositionInputHandler(str) {
             // console.log("onCompositionEnd", str, c.lastValue)
-            clearTimeout(timer);
+            if (timer)
+                clearTimeout(timer);
             str = str.replace(/\x01/g, "");
             if (str == c.lastValue)
                 return "";
-            if (c.lastValue)
+            if (c.lastValue && timer)
                 host.undo();
             return str;
-        }        
+        };
         host.onCompositionEnd();
         host.removeListener("mousedown", onCompositionEnd);
         if (e.type == "compositionend" && c.range) {