diff --git a/compiler/frontend/src/org/jetbrains/kotlin/resolve/lazy/descriptors/LazyClassDescriptor.java b/compiler/frontend/src/org/jetbrains/kotlin/resolve/lazy/descriptors/LazyClassDescriptor.java
index 15fff39e264..54dbdb08454 100644
--- a/compiler/frontend/src/org/jetbrains/kotlin/resolve/lazy/descriptors/LazyClassDescriptor.java
+++ b/compiler/frontend/src/org/jetbrains/kotlin/resolve/lazy/descriptors/LazyClassDescriptor.java
@@ -382,8 +382,10 @@ public class LazyClassDescriptor extends ClassDescriptorBase implements ClassDes
         }
         Name name = ((JetClassOrObjectInfo) classObjectInfo).getName();
         assert name != null;
-        ClassifierDescriptor classObjectDescriptor = getScopeForMemberLookup().getClassifier(name);
+        getScopeForMemberLookup().getClassifier(name);
+        ClassDescriptor classObjectDescriptor = c.getTrace().get(BindingContext.CLASS, classObject);
         if (classObjectDescriptor instanceof LazyClassDescriptor) {
+            assert DescriptorUtils.isClassObject(classObjectDescriptor) : "Not a class object: " + classObjectDescriptor;
             return (LazyClassDescriptor) classObjectDescriptor;
         }
         else {
diff --git a/compiler/testData/diagnostics/tests/classObjects/classObjectRedeclaration.kt b/compiler/testData/diagnostics/tests/classObjects/classObjectRedeclaration.kt
new file mode 100644
index 00000000000..a7dc674c135
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/classObjects/classObjectRedeclaration.kt
@@ -0,0 +1,19 @@
+package test
+
+class A {
+    object <!REDECLARATION!>Default<!>
+
+    <!REDECLARATION!>class object<!>
+}
+
+class B {
+    class object <!REDECLARATION!>Named<!>
+
+    object <!REDECLARATION!>Named<!>
+}
+
+class C {
+    class <!REDECLARATION!>Named<!>
+
+    class object <!REDECLARATION!>Named<!>
+}
\ No newline at end of file
diff --git a/compiler/testData/diagnostics/tests/classObjects/classObjectRedeclaration.txt b/compiler/testData/diagnostics/tests/classObjects/classObjectRedeclaration.txt
new file mode 100644
index 00000000000..6d61dfdaa13
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/classObjects/classObjectRedeclaration.txt
@@ -0,0 +1,67 @@
+package
+
+package test {
+
+    internal final class A {
+        public constructor A()
+        public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+        public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+        public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+
+        internal object Default {
+            private constructor Default()
+            public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+            public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+            public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+        }
+
+        internal class object Default {
+            private constructor Default()
+            public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+            public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+            public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+        }
+    }
+
+    internal final class B {
+        public constructor B()
+        public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+        public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+        public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+
+        internal object Named {
+            private constructor Named()
+            public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+            public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+            public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+        }
+
+        internal class object Named {
+            private constructor Named()
+            public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+            public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+            public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+        }
+    }
+
+    internal final class C {
+        public constructor C()
+        public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+        public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+        public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+
+        internal final class Named {
+            public constructor Named()
+            public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+            public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+            public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+        }
+
+        internal class object Named {
+            private constructor Named()
+            public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+            public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+            public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+        }
+    }
+}
diff --git a/compiler/tests/org/jetbrains/kotlin/checkers/JetDiagnosticsTestGenerated.java b/compiler/tests/org/jetbrains/kotlin/checkers/JetDiagnosticsTestGenerated.java
index fafda7d59af..b91d44a0b6e 100644
--- a/compiler/tests/org/jetbrains/kotlin/checkers/JetDiagnosticsTestGenerated.java
+++ b/compiler/tests/org/jetbrains/kotlin/checkers/JetDiagnosticsTestGenerated.java
@@ -1439,6 +1439,12 @@ public class JetDiagnosticsTestGenerated extends AbstractJetDiagnosticsTest {
                 doTest(fileName);
             }
 
+            @TestMetadata("classObjectRedeclaration.kt")
+            public void testClassObjectRedeclaration() throws Exception {
+                String fileName = JetTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/classObjects/classObjectRedeclaration.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("ClassObjectVisibility.kt")
             public void testClassObjectVisibility() throws Exception {
                 String fileName = JetTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/classObjects/ClassObjectVisibility.kt");