diff --git a/lib/ace/undomanager.js b/lib/ace/undomanager.js
index b99850c1..599e9158 100644
--- a/lib/ace/undomanager.js
+++ b/lib/ace/undomanager.js
@@ -67,9 +67,9 @@ var UndoManager = function() {
         this.$redoStack = [];
 
         if (this.dirtyCounter < 0) {
-          // The user has made a change after undoing past the last clean state.
-          // We can never get back to a clean state now until markClean() is called.
-          this.dirtyCounter = NaN;
+            // The user has made a change after undoing past the last clean state.
+            // We can never get back to a clean state now until markClean() is called.
+            this.dirtyCounter = NaN;
         }
         this.dirtyCounter++;
     };