diff --git a/platform/lang-impl/src/com/intellij/util/CompletionContributorForTextField.java b/platform/lang-impl/src/com/intellij/util/CompletionContributorForTextField.java
index b7f2eb6a8163..9281cccf439e 100644
--- a/platform/lang-impl/src/com/intellij/util/CompletionContributorForTextField.java
+++ b/platform/lang-impl/src/com/intellij/util/CompletionContributorForTextField.java
@@ -3,25 +3,26 @@ package com.intellij.util;
 import com.intellij.codeInsight.completion.CompletionContributor;
 import com.intellij.codeInsight.completion.CompletionParameters;
 import com.intellij.codeInsight.completion.CompletionResultSet;
-import com.intellij.openapi.application.ApplicationManager;
+import com.intellij.openapi.project.DumbAware;
+import com.intellij.openapi.project.DumbService;
 import com.intellij.psi.PsiFile;
 import com.intellij.psi.PsiPlainTextFile;
 
 /**
  * @author sergey.evdokimov
  */
-public class CompletionContributorForTextField extends CompletionContributor {
+public class CompletionContributorForTextField extends CompletionContributor implements DumbAware {
 
   @Override
   public void fillCompletionVariants(CompletionParameters parameters, CompletionResultSet result) {
     PsiFile file = parameters.getOriginalFile();
     if (!(file instanceof PsiPlainTextFile)) return;
 
-    ApplicationManager.getApplication().assertReadAccessAllowed();
-
     TextFieldCompletionProvider field = file.getUserData(TextFieldCompletionProvider.COMPLETING_TEXT_FIELD_KEY);
     if (field == null) return;
 
+    if (!(field instanceof DumbAware) && DumbService.isDumb(file.getProject())) return;
+    
     String text = file.getText();
     int offset = Math.min(text.length(), parameters.getOffset());
 
diff --git a/platform/lang-impl/src/com/intellij/util/TextFieldCompletionProviderDumbAware.java b/platform/lang-impl/src/com/intellij/util/TextFieldCompletionProviderDumbAware.java
new file mode 100644
index 000000000000..e118f7fcea43
--- /dev/null
+++ b/platform/lang-impl/src/com/intellij/util/TextFieldCompletionProviderDumbAware.java
@@ -0,0 +1,10 @@
+package com.intellij.util;
+
+import com.intellij.openapi.project.DumbAware;
+
+/**
+ * @author sergey.evdokimov
+ */
+public abstract class TextFieldCompletionProviderDumbAware extends TextFieldCompletionProvider implements DumbAware {
+
+}
diff --git a/plugins/git4idea/src/git4idea/history/wholeTree/UsersFilterAction.java b/plugins/git4idea/src/git4idea/history/wholeTree/UsersFilterAction.java
index fbc090195865..22066bec2fef 100644
--- a/plugins/git4idea/src/git4idea/history/wholeTree/UsersFilterAction.java
+++ b/plugins/git4idea/src/git4idea/history/wholeTree/UsersFilterAction.java
@@ -35,6 +35,7 @@ import com.intellij.ui.EditorTextField;
 import com.intellij.ui.EditorTextFieldProvider;
 import com.intellij.util.Consumer;
 import com.intellij.util.TextFieldCompletionProvider;
+import com.intellij.util.TextFieldCompletionProviderDumbAware;
 import git4idea.history.NewGitUsersComponent;
 import org.jetbrains.annotations.NotNull;
 
@@ -151,7 +152,7 @@ public class UsersFilterAction extends BasePopupAction {
     myEditorField.setOneLineMode(false);
     panel.add(myEditorField, BorderLayout.CENTER);
 
-    myTextFieldCompletionProvider = new TextFieldCompletionProvider() {
+    myTextFieldCompletionProvider = new TextFieldCompletionProviderDumbAware() {
       @NotNull
       @Override
       protected String getPrefix(@NotNull String currentTextPrefix) {
diff --git a/plugins/groovy/src/org/jetbrains/plugins/groovy/mvc/MvcRunTargetDialog.java b/plugins/groovy/src/org/jetbrains/plugins/groovy/mvc/MvcRunTargetDialog.java
index 2227fdf71f3b..f9c4ff502463 100644
--- a/plugins/groovy/src/org/jetbrains/plugins/groovy/mvc/MvcRunTargetDialog.java
+++ b/plugins/groovy/src/org/jetbrains/plugins/groovy/mvc/MvcRunTargetDialog.java
@@ -28,6 +28,7 @@ import com.intellij.openapi.util.text.StringUtil;
 import com.intellij.ui.*;
 import com.intellij.util.ArrayUtil;
 import com.intellij.util.TextFieldCompletionProvider;
+import com.intellij.util.TextFieldCompletionProviderDumbAware;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.plugins.groovy.mvc.util.ModuleCellRenderer;
 import org.jetbrains.plugins.groovy.mvc.util.MvcTargetDialogCompletionUtils;
@@ -148,7 +149,7 @@ public class MvcRunTargetDialog extends DialogWrapper {
     myFakePanel = new JPanel(new BorderLayout());
     myFakePanel.add(myTargetField, BorderLayout.CENTER);
 
-    TextFieldCompletionProvider vmOptionCompletionProvider = new TextFieldCompletionProvider() {
+    TextFieldCompletionProvider vmOptionCompletionProvider = new TextFieldCompletionProviderDumbAware() {
       @NotNull
       @Override
       protected String getPrefix(@NotNull String currentTextPrefix) {
@@ -164,7 +165,7 @@ public class MvcRunTargetDialog extends DialogWrapper {
     };
     myVmOptionsField = vmOptionCompletionProvider.createEditor(myModule.getProject());
 
-    new TextFieldCompletionProvider() {
+    new TextFieldCompletionProviderDumbAware() {
 
       @NotNull
       @Override