diff --git a/idea/src/org/jetbrains/jet/plugin/util/InfinitePeriodicalTask.java b/idea/src/org/jetbrains/jet/plugin/util/InfinitePeriodicalTask.java
index 43a146d505a..50233e0a1f2 100644
--- a/idea/src/org/jetbrains/jet/plugin/util/InfinitePeriodicalTask.java
+++ b/idea/src/org/jetbrains/jet/plugin/util/InfinitePeriodicalTask.java
@@ -42,13 +42,17 @@ public class InfinitePeriodicalTask {
             public void run() {
                 myUpdateAlarm.addRequest(this, delay);
                 LongRunningReadTask task = taskProvider.compute();
-                task.init();
+
+                boolean invalidRequest = !task.init();
 
                 //noinspection unchecked
                 if (task.shouldStart(currentTask)) {
                     currentTask = task;
                     currentTask.run();
                 }
+                else if (invalidRequest) {
+                    currentTask = null;
+                }
             }
         }, delay);
 
diff --git a/idea/src/org/jetbrains/jet/plugin/util/LongRunningReadTask.java b/idea/src/org/jetbrains/jet/plugin/util/LongRunningReadTask.java
index 06b28b4bc71..2d7e08c4552 100644
--- a/idea/src/org/jetbrains/jet/plugin/util/LongRunningReadTask.java
+++ b/idea/src/org/jetbrains/jet/plugin/util/LongRunningReadTask.java
@@ -125,11 +125,18 @@ public abstract class LongRunningReadTask<RequestInfo, ResultData> {
         });
     }
 
-    public final void init() {
+    /**
+     * Executed in GUI Thread.
+     *
+     * @return true if new request was successfully created, false if request is invalid and shouldn't be started
+     */
+    public final boolean init() {
         ApplicationManager.getApplication().assertIsDispatchThread();
 
         requestInfo = prepareRequestInfo();
         currentState = State.INITIALIZED;
+
+        return requestInfo != null;
     }
 
     private void resultReady(ResultData resultData) {