diff --git a/platform/lang-impl/src/com/intellij/ide/navigationToolbar/NavBarUpdateQueue.java b/platform/lang-impl/src/com/intellij/ide/navigationToolbar/NavBarUpdateQueue.java
index e9e0e127d6e3..297334710c06 100644
--- a/platform/lang-impl/src/com/intellij/ide/navigationToolbar/NavBarUpdateQueue.java
+++ b/platform/lang-impl/src/com/intellij/ide/navigationToolbar/NavBarUpdateQueue.java
@@ -117,7 +117,9 @@ public class NavBarUpdateQueue extends MergingUpdateQueue {
 
   void restartRebuild() {
     myUserActivityAlarm.cancelAllRequests();
-    myUserActivityAlarm.addRequest(myUserActivityAlarmRunnable, Registry.intValue("navBar.userActivityMergeTime"));
+    if (!myUserActivityAlarm.isDisposed()) {
+      myUserActivityAlarm.addRequest(myUserActivityAlarmRunnable, Registry.intValue("navBar.userActivityMergeTime"));
+    }
   }
 
   private void processUserActivity() {