diff --git a/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/completion/GroovyNoVariantsDelegator.java b/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/completion/GroovyNoVariantsDelegator.java
index ef74cc4702e9..957e080bd9f0 100644
--- a/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/completion/GroovyNoVariantsDelegator.java
+++ b/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/completion/GroovyNoVariantsDelegator.java
@@ -30,7 +30,8 @@ public class GroovyNoVariantsDelegator extends NoVariantsDelegator {
     if (parameters.getCompletionType() == CompletionType.BASIC &&
         parameters.getInvocationCount() <= 1 &&
         JavaCompletionContributor.mayStartClassName(result, false) &&
-        GroovyCompletionContributor.isClassNamePossible(parameters.getPosition())) {
+        GroovyCompletionContributor.isClassNamePossible(parameters.getPosition()) &&
+        !MapArgumentCompletionProvider.isMapKeyCompletion(parameters)) {
       final ClassByNameMerger merger = new ClassByNameMerger(parameters.getInvocationCount() == 0, result);
 
       GroovyCompletionContributor.addAllClasses(parameters, result,
diff --git a/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/completion/MapArgumentCompletionProvider.java b/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/completion/MapArgumentCompletionProvider.java
index 96379c531464..84b6b2808589 100644
--- a/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/completion/MapArgumentCompletionProvider.java
+++ b/plugins/groovy/src/org/jetbrains/plugins/groovy/lang/completion/MapArgumentCompletionProvider.java
@@ -23,6 +23,7 @@ import com.intellij.psi.PsiElement;
 import com.intellij.psi.PsiRecursiveElementWalkingVisitor;
 import com.intellij.util.ProcessingContext;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 import org.jetbrains.plugins.groovy.GroovyIcons;
 import org.jetbrains.plugins.groovy.extensions.GroovyNamedArgumentProvider;
 import org.jetbrains.plugins.groovy.extensions.NamedArgumentDescriptor;
@@ -70,21 +71,13 @@ class MapArgumentCompletionProvider extends CompletionProvider<CompletionParamet
   protected void addCompletions(@NotNull CompletionParameters parameters,
                                 ProcessingContext context,
                                 @NotNull CompletionResultSet result) {
-    PsiElement mapOrArgumentList;
-
-    PsiElement parent = parameters.getPosition().getParent();
-    if (parent instanceof GrReferenceExpression) {
-      if (((GrReferenceExpression)parent).getQualifier() != null) return;
-      mapOrArgumentList = parent.getParent();
-    }
-    else {
-      mapOrArgumentList = parent.getParent().getParent();
+    PsiElement mapOrArgumentList = findMapOrArgumentList(parameters);
+    if (mapOrArgumentList == null) {
+      return;
     }
 
-    if (mapOrArgumentList instanceof GrListOrMap) {
-      if (((GrListOrMap)mapOrArgumentList).getNamedArguments().length > 0) {
-        result.stopHere();
-      }
+    if (isMapKeyCompletion(parameters)) {
+      result.stopHere();
     }
 
     Map<String, NamedArgumentDescriptor> map = calcNamedArgumentsForCall(mapOrArgumentList);
@@ -113,6 +106,24 @@ class MapArgumentCompletionProvider extends CompletionProvider<CompletionParamet
 
   }
 
+  public static boolean isMapKeyCompletion(CompletionParameters parameters) {
+    PsiElement mapOrArgumentList = findMapOrArgumentList(parameters);
+    return mapOrArgumentList instanceof GrListOrMap && ((GrListOrMap)mapOrArgumentList).getNamedArguments().length > 0;
+  }
+
+  @Nullable
+  private static PsiElement findMapOrArgumentList(CompletionParameters parameters) {
+    PsiElement parent = parameters.getPosition().getParent();
+    if (parent instanceof GrReferenceExpression) {
+      if (((GrReferenceExpression)parent).getQualifier() != null) return null;
+      return parent.getParent();
+    }
+    if (parent == null || parent.getParent() == null) {
+      return null;
+    }
+    return parent.getParent().getParent();
+  }
+
   private static Map<String, NamedArgumentDescriptor> findOtherNamedArgumentsInFile(PsiElement mapOrArgumentList) {
     final Map<String, NamedArgumentDescriptor> map = new HashMap<String, NamedArgumentDescriptor>();
     mapOrArgumentList.getContainingFile().accept(new PsiRecursiveElementWalkingVisitor() {
@@ -145,7 +156,7 @@ class MapArgumentCompletionProvider extends CompletionProvider<CompletionParamet
     return GrNamedArgument.EMPTY_ARRAY;
   }
 
-  private static Map<String, NamedArgumentDescriptor> calcNamedArgumentsForCall(PsiElement mapOrArgumentList) {
+  private static Map<String, NamedArgumentDescriptor> calcNamedArgumentsForCall(@NotNull PsiElement mapOrArgumentList) {
     PsiElement argumentList = mapOrArgumentList instanceof GrArgumentList ? mapOrArgumentList : mapOrArgumentList.getParent();
     if (argumentList instanceof GrArgumentList) {
       if (mapOrArgumentList instanceof GrListOrMap) {
diff --git a/plugins/groovy/test/org/jetbrains/plugins/groovy/completion/GroovyCompletionTest.groovy b/plugins/groovy/test/org/jetbrains/plugins/groovy/completion/GroovyCompletionTest.groovy
index 23b18f2a4c25..5048a4c08756 100644
--- a/plugins/groovy/test/org/jetbrains/plugins/groovy/completion/GroovyCompletionTest.groovy
+++ b/plugins/groovy/test/org/jetbrains/plugins/groovy/completion/GroovyCompletionTest.groovy
@@ -840,6 +840,11 @@ return foo()"""
     doVariantableTest 'foo1', 'foo3', 'foo4', 'Foo5', 'Foo7'
   }
 
+  public void testNoClassesAsMapKeys() throws Exception {
+    CodeInsightSettings.instance.COMPLETION_CASE_SENSITIVE = CodeInsightSettings.NONE
+    doVariantableTest()
+  }
+
   public void testNamedArgsUsedInFile() throws Exception {
     myFixture.configureByFile(getTestName(false) + ".groovy");
     doVariantableTest 'false', 'foo2', 'float', 'foo1', 'foo3', 'foo4', 'foo5'
diff --git a/plugins/groovy/testdata/groovy/completion/NoClassesAsMapKeys.groovy b/plugins/groovy/testdata/groovy/completion/NoClassesAsMapKeys.groovy
new file mode 100644
index 000000000000..6bff03f999a8
--- /dev/null
+++ b/plugins/groovy/testdata/groovy/completion/NoClassesAsMapKeys.groovy
@@ -0,0 +1 @@
+[foo6:'aaa', d<caret>]
\ No newline at end of file