diff --git a/idea/src/org/jetbrains/jet/lang/descriptors/ClassDescriptor.java b/idea/src/org/jetbrains/jet/lang/descriptors/ClassDescriptor.java
index c1e631da433..6058eec9ff8 100644
--- a/idea/src/org/jetbrains/jet/lang/descriptors/ClassDescriptor.java
+++ b/idea/src/org/jetbrains/jet/lang/descriptors/ClassDescriptor.java
@@ -41,4 +41,6 @@ public interface ClassDescriptor extends ClassifierDescriptor {
 
     @Nullable
     JetType getClassObjectType();
+
+    boolean isObject();
 }
diff --git a/idea/src/org/jetbrains/jet/lang/descriptors/ClassDescriptorImpl.java b/idea/src/org/jetbrains/jet/lang/descriptors/ClassDescriptorImpl.java
index 4ac2c055f56..0dc3449563c 100644
--- a/idea/src/org/jetbrains/jet/lang/descriptors/ClassDescriptorImpl.java
+++ b/idea/src/org/jetbrains/jet/lang/descriptors/ClassDescriptorImpl.java
@@ -90,6 +90,11 @@ public class ClassDescriptorImpl extends DeclarationDescriptorImpl implements Cl
         return null;
     }
 
+    @Override
+    public boolean isObject() {
+        return false;
+    }
+
     @Override
     public boolean isClassObjectAValue() {
         return true;
diff --git a/idea/src/org/jetbrains/jet/lang/descriptors/LazySubstitutingClassDescriptor.java b/idea/src/org/jetbrains/jet/lang/descriptors/LazySubstitutingClassDescriptor.java
index 4ebb5a6f46c..d161f2e5963 100644
--- a/idea/src/org/jetbrains/jet/lang/descriptors/LazySubstitutingClassDescriptor.java
+++ b/idea/src/org/jetbrains/jet/lang/descriptors/LazySubstitutingClassDescriptor.java
@@ -95,6 +95,11 @@ public class LazySubstitutingClassDescriptor implements ClassDescriptor {
         return original.getClassObjectType();
     }
 
+    @Override
+    public boolean isObject() {
+        return original.isObject();
+    }
+
     @Override
     public boolean isClassObjectAValue() {
         return original.isClassObjectAValue();
diff --git a/idea/src/org/jetbrains/jet/lang/descriptors/MutableClassDescriptor.java b/idea/src/org/jetbrains/jet/lang/descriptors/MutableClassDescriptor.java
index 221d4709366..ad6278053e4 100644
--- a/idea/src/org/jetbrains/jet/lang/descriptors/MutableClassDescriptor.java
+++ b/idea/src/org/jetbrains/jet/lang/descriptors/MutableClassDescriptor.java
@@ -30,12 +30,18 @@ public class MutableClassDescriptor extends MutableDeclarationDescriptor impleme
     private MutableClassDescriptor classObjectDescriptor;
     private JetType classObjectType;
     private JetType defaultType;
+    private final boolean isObject;
 
     public MutableClassDescriptor(@NotNull BindingTrace trace, @NotNull DeclarationDescriptor containingDeclaration, @NotNull JetScope outerScope) {
+        this(trace, containingDeclaration, outerScope, false);
+    }
+
+    public MutableClassDescriptor(@NotNull BindingTrace trace, @NotNull DeclarationDescriptor containingDeclaration, @NotNull JetScope outerScope, boolean isObject) {
         super(containingDeclaration);
         this.scopeForMemberLookup = new WritableScopeImpl(JetScope.EMPTY, this, trace.getErrorHandler()).setDebugName("MemberLookup");
         this.scopeForSupertypeResolution = new WritableScopeImpl(outerScope, this, trace.getErrorHandler()).setDebugName("SupertypeResolution");
         this.scopeForMemberResolution = new WritableScopeImpl(new ChainedScope(this, scopeForMemberLookup, scopeForSupertypeResolution), this, trace.getErrorHandler()).setDebugName("MemberResolution");
+        this.isObject = isObject;
     }
 
 ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
@@ -43,6 +49,7 @@ public class MutableClassDescriptor extends MutableDeclarationDescriptor impleme
     @Override
     public ClassObjectStatus setClassObjectDescriptor(@NotNull MutableClassDescriptor classObjectDescriptor) {
         if (this.classObjectDescriptor != null) return ClassObjectStatus.DUPLICATE;
+        assert classObjectDescriptor.isObject();
         this.classObjectDescriptor = classObjectDescriptor;
         return ClassObjectStatus.OK;
     }
@@ -242,6 +249,11 @@ public class MutableClassDescriptor extends MutableDeclarationDescriptor impleme
         return !constructors.isEmpty();
     }
 
+    @Override
+    public boolean isObject() {
+        return isObject;
+    }
+
     @Override
     public String toString() {
         return DescriptorRenderer.TEXT_FOR_DEBUG.render(this) + "[" + getClass().getCanonicalName() + "@" + System.identityHashCode(this) + "]";
diff --git a/idea/src/org/jetbrains/jet/lang/resolve/TopDownAnalyzer.java b/idea/src/org/jetbrains/jet/lang/resolve/TopDownAnalyzer.java
index ae6c3940658..1d02b9eacc5 100644
--- a/idea/src/org/jetbrains/jet/lang/resolve/TopDownAnalyzer.java
+++ b/idea/src/org/jetbrains/jet/lang/resolve/TopDownAnalyzer.java
@@ -171,7 +171,7 @@ public class TopDownAnalyzer {
                     MutableClassDescriptor mutableClassDescriptor = new MutableClassDescriptor(trace, owner, outerScope);
 
                     if (klass.hasModifier(JetTokens.ENUM_KEYWORD)) {
-                        MutableClassDescriptor classObjectDescriptor = new MutableClassDescriptor(trace, mutableClassDescriptor, outerScope);
+                        MutableClassDescriptor classObjectDescriptor = new MutableClassDescriptor(trace, mutableClassDescriptor, outerScope, true);
                         classObjectDescriptor.setName("class-object-for-" + klass.getName());
                         classObjectDescriptor.createTypeConstructor();
                         createPrimaryConstructor(classObjectDescriptor);
@@ -213,7 +213,7 @@ public class TopDownAnalyzer {
                 }
 
                 private MutableClassDescriptor createClassDescriptorForObject(@NotNull JetClassOrObject declaration, @NotNull NamespaceLike owner) {
-                    MutableClassDescriptor mutableClassDescriptor = new MutableClassDescriptor(trace, owner, outerScope) {
+                    MutableClassDescriptor mutableClassDescriptor = new MutableClassDescriptor(trace, owner, outerScope, true) {
                         @Override
                         public ClassObjectStatus setClassObjectDescriptor(@NotNull MutableClassDescriptor classObjectDescriptor) {
                             return ClassObjectStatus.NOT_ALLOWED;
diff --git a/idea/src/org/jetbrains/jet/lang/resolve/java/JavaClassDescriptor.java b/idea/src/org/jetbrains/jet/lang/resolve/java/JavaClassDescriptor.java
index a3ce03a10b1..34d6f0d7a26 100644
--- a/idea/src/org/jetbrains/jet/lang/resolve/java/JavaClassDescriptor.java
+++ b/idea/src/org/jetbrains/jet/lang/resolve/java/JavaClassDescriptor.java
@@ -109,6 +109,11 @@ public class JavaClassDescriptor extends MutableDeclarationDescriptor implements
         return classObjectType;
     }
 
+    @Override
+    public boolean isObject() {
+        return false;
+    }
+
     @Override
     public boolean isClassObjectAValue() {
         return false;