--- src/core/org/apache/jmeter/gui/GuiPackage.java	(revision 1624847)
+++ src/core/org/apache/jmeter/gui/GuiPackage.java	(working copy)
@@ -137,7 +137,9 @@ 
      */
     private GuiPackage(JMeterTreeModel treeModel, JMeterTreeListener treeListener) {
         this.treeModel = treeModel;
-        this.treeModel.addTreeModelListener(undoHistory);
+        if(undoHistory.isEnabled()) {
+            this.treeModel.addTreeModelListener(undoHistory);
+        }
         this.treeListener = treeListener;
     }
 
@@ -156,7 +158,9 @@ 
      * - Locale Changes
      */
     public void registerAsListener() {
-        this.undoHistory.registerHistoryListener(this);
+        if(undoHistory.isEnabled()) {
+            this.undoHistory.registerHistoryListener(this);
+        }
         JMeterUtils.addLocaleChangeListener(this);
     }
 
--- src/core/org/apache/jmeter/gui/UndoHistory.java	(revision 1624847)
+++ src/core/org/apache/jmeter/gui/UndoHistory.java	(working copy)
@@ -133,6 +133,11 @@ 
      * @param comment   String
      */
     public void add(JMeterTreeModel treeModel, String comment) {
+        if(!isEnabled()) {
+            log.debug("undo.history.size is set to 0, undo/redo feature is disabled");
+            return;
+        }
+
         // don't add element if we are in the middle of undo/redo or a big loading
         if (working) {
             log.debug("Not adding history because of noop");
@@ -338,6 +343,14 @@ 
     }
     
     /**
+     * 
+     * @return true if history is enabled
+     */
+    boolean isEnabled() {
+        return HISTORY_SIZE > 0;
+    }
+    
+    /**
      * Register HistoryListener 
      * @param listener
      */