diff --git a/platform/lang-impl/src/com/intellij/codeInsight/completion/CompletionProgressIndicator.java b/platform/lang-impl/src/com/intellij/codeInsight/completion/CompletionProgressIndicator.java
index 6448270f048b..e842a0efbe29 100644
--- a/platform/lang-impl/src/com/intellij/codeInsight/completion/CompletionProgressIndicator.java
+++ b/platform/lang-impl/src/com/intellij/codeInsight/completion/CompletionProgressIndicator.java
@@ -636,6 +636,7 @@ public class CompletionProgressIndicator extends ProgressIndicatorBase implement
     final int offset = myEditor.getCaretModel().getOffset();
     final long stamp = myEditor.getDocument().getModificationStamp();
     final Project project = getProject();
+    final boolean wasDumb = DumbService.getInstance(project).isDumb();
     ApplicationManager.getApplication().invokeLater(new Runnable() {
       @Override
       public void run() {
@@ -647,6 +648,10 @@ public class CompletionProgressIndicator extends ProgressIndicatorBase implement
           return;
         }
 
+        if (!wasDumb && DumbService.getInstance(project).isDumb()) {
+          return;
+        }
+
         if (myEditor.getCaretModel().getOffset() != offset || myEditor.getDocument().getModificationStamp() != stamp) {
           return;
         }
diff --git a/platform/lang-impl/src/com/intellij/codeInsight/editorActions/CompletionAutoPopupHandler.java b/platform/lang-impl/src/com/intellij/codeInsight/editorActions/CompletionAutoPopupHandler.java
index 3be94618a300..a84084c87322 100644
--- a/platform/lang-impl/src/com/intellij/codeInsight/editorActions/CompletionAutoPopupHandler.java
+++ b/platform/lang-impl/src/com/intellij/codeInsight/editorActions/CompletionAutoPopupHandler.java
@@ -34,6 +34,7 @@ import com.intellij.openapi.fileEditor.FileEditorManagerAdapter;
 import com.intellij.openapi.fileEditor.FileEditorManagerEvent;
 import com.intellij.openapi.fileEditor.FileEditorManagerListener;
 import com.intellij.openapi.fileTypes.FileType;
+import com.intellij.openapi.project.DumbService;
 import com.intellij.openapi.project.Project;
 import com.intellij.openapi.util.Key;
 import com.intellij.psi.PsiFile;
@@ -98,6 +99,7 @@ public class CompletionAutoPopupHandler extends TypedHandlerDelegate {
         if (project.isDisposed() || !file.isValid()) return;
         if (editor.isDisposed() || isMainEditor && FileEditorManager.getInstance(project).getSelectedTextEditor() != editor) return;
         if (ApplicationManager.getApplication().isWriteAccessAllowed()) return; //it will fail anyway
+        if (DumbService.getInstance(project).isDumb()) return;
 
         new CodeCompletionHandlerBase(CompletionType.BASIC, false, true).invoke(project, editor);