diff --git a/compiler/frontend/src/org/jetbrains/jet/lang/resolve/JetModuleUtil.java b/compiler/frontend/src/org/jetbrains/jet/lang/resolve/JetModuleUtil.java
index 246083acff6..8e856487338 100644
--- a/compiler/frontend/src/org/jetbrains/jet/lang/resolve/JetModuleUtil.java
+++ b/compiler/frontend/src/org/jetbrains/jet/lang/resolve/JetModuleUtil.java
@@ -19,11 +19,12 @@ package org.jetbrains.jet.lang.resolve;
 import org.jetbrains.jet.lang.psi.JetElement;
 import org.jetbrains.jet.lang.resolve.name.SpecialNames;
 import org.jetbrains.jet.lang.resolve.scopes.JetScope;
+import org.jetbrains.jet.lang.resolve.scopes.receivers.ReceiverValue;
 import org.jetbrains.jet.lang.types.NamespaceType;
 
 public class JetModuleUtil {
     public static NamespaceType getRootNamespaceType(JetElement expression) {
         // TODO: this is a stub: at least the modules' root namespaces must be indexed here
-        return new NamespaceType(SpecialNames.ROOT_NAMESPACE, JetScope.EMPTY);
+        return new NamespaceType(SpecialNames.ROOT_NAMESPACE, JetScope.EMPTY, ReceiverValue.NO_RECEIVER);
     }
 }
diff --git a/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/CallExpressionResolver.java b/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/CallExpressionResolver.java
index bd0cb4c74fc..b4a4c0100f0 100644
--- a/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/CallExpressionResolver.java
+++ b/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/CallExpressionResolver.java
@@ -52,6 +52,7 @@ import java.util.List;
 import static org.jetbrains.jet.lang.diagnostics.Errors.*;
 import static org.jetbrains.jet.lang.resolve.BindingContext.*;
 import static org.jetbrains.jet.lang.resolve.DescriptorUtils.getStaticNestedClassesScope;
+import static org.jetbrains.jet.lang.resolve.scopes.receivers.ReceiverValue.NO_RECEIVER;
 import static org.jetbrains.jet.lang.types.TypeUtils.NO_EXPECTED_TYPE;
 import static org.jetbrains.jet.lang.psi.JetPsiUtil.isLHSOfDot;
 
@@ -113,7 +114,7 @@ public class CallExpressionResolver {
                                 return "Scope for the type parameter on the left hand side of dot";
                             }
                         };
-            return new NamespaceType(referencedName, scopeForStaticMembersResolution);
+            return new NamespaceType(referencedName, scopeForStaticMembersResolution, NO_RECEIVER);
         }
         temporaryTrace.commit();
         return result[0];
@@ -154,7 +155,7 @@ public class CallExpressionResolver {
             }
 
             JetScope scope = new ChainedScope(classifier, scopes.toArray(new JetScope[scopes.size()]));
-            return new NamespaceType(referencedName, scope);
+            return new NamespaceType(referencedName, scope, new ExpressionReceiver(expression, classObjectType));
         }
         return classObjectType;
     }
@@ -195,7 +196,7 @@ public class CallExpressionResolver {
         else {
             scope = namespace.getMemberScope();
         }
-        return new NamespaceType(name, scope);
+        return new NamespaceType(name, scope, NO_RECEIVER);
     }
 
     @Nullable
diff --git a/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/tasks/TaskPrioritizer.java b/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/tasks/TaskPrioritizer.java
index 5f5b9ef845c..1ae1e1d185e 100644
--- a/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/tasks/TaskPrioritizer.java
+++ b/compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/tasks/TaskPrioritizer.java
@@ -18,6 +18,7 @@ package org.jetbrains.jet.lang.resolve.calls.tasks;
 
 import com.google.common.collect.Lists;
 import com.intellij.openapi.progress.ProgressIndicatorProvider;
+import com.intellij.openapi.util.Pair;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.jetbrains.jet.lang.descriptors.*;
@@ -25,7 +26,6 @@ import org.jetbrains.jet.lang.psi.JetExpression;
 import org.jetbrains.jet.lang.psi.JetReferenceExpression;
 import org.jetbrains.jet.lang.psi.JetSuperExpression;
 import org.jetbrains.jet.lang.resolve.DescriptorUtils;
-import org.jetbrains.jet.lang.resolve.LibrarySourceHacks;
 import org.jetbrains.jet.lang.resolve.calls.autocasts.AutoCastServiceImpl;
 import org.jetbrains.jet.lang.resolve.calls.context.BasicCallResolutionContext;
 import org.jetbrains.jet.lang.resolve.name.Name;
@@ -34,9 +34,11 @@ import org.jetbrains.jet.lang.resolve.scopes.JetScopeUtils;
 import org.jetbrains.jet.lang.resolve.scopes.receivers.ExpressionReceiver;
 import org.jetbrains.jet.lang.resolve.scopes.receivers.ReceiverValue;
 import org.jetbrains.jet.lang.types.ErrorUtils;
+import org.jetbrains.jet.lang.types.JetType;
 import org.jetbrains.jet.lang.types.NamespaceType;
 import org.jetbrains.jet.lang.types.checker.JetTypeChecker;
 
+import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
@@ -82,20 +84,27 @@ public class TaskPrioritizer {
             @NotNull JetReferenceExpression functionReference,
             @NotNull List<CallableDescriptorCollector<? extends D>> callableDescriptorCollectors
     ) {
+        List<Pair<JetScope, ReceiverValue>> variants = new ArrayList<Pair<JetScope, ReceiverValue>>(2);
+
         ReceiverValue explicitReceiver = context.call.getExplicitReceiver();
-        JetScope scope;
         if (explicitReceiver.exists() && explicitReceiver.getType() instanceof NamespaceType) {
-            // Receiver is a namespace
-            scope = explicitReceiver.getType().getMemberScope();
-            explicitReceiver = NO_RECEIVER;
+            JetType receiverType = explicitReceiver.getType();
+            variants.add(Pair.create(receiverType.getMemberScope(), NO_RECEIVER));
+            ReceiverValue value = ((NamespaceType) receiverType).getReceiverValue();
+            if (value.exists()) {
+                variants.add(Pair.create(context.scope, value));
+            }
         }
         else {
-            scope = context.scope;
+            variants.add(Pair.create(context.scope, explicitReceiver));
+        }
+
+        ResolutionTaskHolder<D, F> result =
+                new ResolutionTaskHolder<D, F>(functionReference, context, new MyPriorityProvider<D>(context), null);
+        for (Pair<JetScope, ReceiverValue> pair : variants) {
+            doComputeTasks(pair.second, new TaskPrioritizerContext<D, F>(name, result, context, pair.first, callableDescriptorCollectors));
         }
 
-        ResolutionTaskHolder<D, F> result = new ResolutionTaskHolder<D, F>(functionReference, context, new MyPriorityProvider<D>(context), null);
-        TaskPrioritizerContext<D, F> c = new TaskPrioritizerContext<D, F>(name, result, context, scope, callableDescriptorCollectors);
-        doComputeTasks(explicitReceiver, c);
         return result.getTasks();
     }
 
diff --git a/compiler/testData/codegen/box/classes/classObjectToString.kt b/compiler/testData/codegen/box/classes/classObjectToString.kt
new file mode 100644
index 00000000000..b6fdee98c38
--- /dev/null
+++ b/compiler/testData/codegen/box/classes/classObjectToString.kt
@@ -0,0 +1,7 @@
+class SomeClass { class object }
+
+fun box() = 
+    if ((SomeClass.toString() as java.lang.String).matches("SomeClass\\\$object@[0-9a-fA-F]+"))
+        "OK"
+    else
+        "Fail: $SomeClass"
diff --git a/compiler/testData/diagnostics/tests/extensions/classObject.kt b/compiler/testData/diagnostics/tests/extensions/classObject.kt
new file mode 100644
index 00000000000..762a9d836d7
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/extensions/classObject.kt
@@ -0,0 +1,19 @@
+trait Tr
+
+class A { class object }
+class B { class object : Tr }
+
+fun Any.f1() {}
+fun Any?.f2() {}
+fun Tr.f3() {}
+fun Tr?.f4() {}
+fun A.f5() {}
+
+fun test() {
+    A.f1()
+    A.f2()
+    B.f3()
+    B.f4()
+    A.<!UNRESOLVED_REFERENCE_WRONG_RECEIVER!>f5<!>()
+    B.<!UNRESOLVED_REFERENCE_WRONG_RECEIVER!>f5<!>()
+}
\ No newline at end of file
diff --git a/compiler/testData/diagnostics/tests/extensions/kt3470.kt b/compiler/testData/diagnostics/tests/extensions/kt3470.kt
new file mode 100644
index 00000000000..720e19f2009
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/extensions/kt3470.kt
@@ -0,0 +1,7 @@
+class A {
+    class object {
+        fun foo() = toString()
+    }
+}
+
+val a = A.toString()
diff --git a/compiler/testData/diagnostics/tests/extensions/noClassObjectsInJava.kt b/compiler/testData/diagnostics/tests/extensions/noClassObjectsInJava.kt
new file mode 100644
index 00000000000..619baea05d3
--- /dev/null
+++ b/compiler/testData/diagnostics/tests/extensions/noClassObjectsInJava.kt
@@ -0,0 +1,11 @@
+// FILE: A.java
+public class A {
+    public static void foo() {}
+    public static class Nested {}
+}
+
+// FILE: B.kt
+fun Any?.bar() = 42
+
+fun f1() = A.<!UNRESOLVED_REFERENCE!>bar<!>()
+fun f2() = A.Nested.<!UNRESOLVED_REFERENCE!>bar<!>()
diff --git a/compiler/tests/org/jetbrains/jet/checkers/JetDiagnosticsTestGenerated.java b/compiler/tests/org/jetbrains/jet/checkers/JetDiagnosticsTestGenerated.java
index 62b71a4fd3e..992e316f8c5 100644
--- a/compiler/tests/org/jetbrains/jet/checkers/JetDiagnosticsTestGenerated.java
+++ b/compiler/tests/org/jetbrains/jet/checkers/JetDiagnosticsTestGenerated.java
@@ -2674,6 +2674,11 @@ public class JetDiagnosticsTestGenerated extends AbstractDiagnosticsTestWithEage
                 JetTestUtils.assertAllTestsPresentByMetadata(this.getClass(), "org.jetbrains.jet.generators.tests.GenerateTests", new File("compiler/testData/diagnostics/tests/extensions"), Pattern.compile("^(.+)\\.kt$"), true);
             }
             
+            @TestMetadata("classObject.kt")
+            public void testClassObject() throws Exception {
+                doTest("compiler/testData/diagnostics/tests/extensions/classObject.kt");
+            }
+            
             @TestMetadata("ExtensionFunctions.kt")
             public void testExtensionFunctions() throws Exception {
                 doTest("compiler/testData/diagnostics/tests/extensions/ExtensionFunctions.kt");
@@ -2704,6 +2709,11 @@ public class JetDiagnosticsTestGenerated extends AbstractDiagnosticsTestWithEage
                 doTest("compiler/testData/diagnostics/tests/extensions/kt2317.kt");
             }
             
+            @TestMetadata("kt3470.kt")
+            public void testKt3470() throws Exception {
+                doTest("compiler/testData/diagnostics/tests/extensions/kt3470.kt");
+            }
+            
             @TestMetadata("kt3563.kt")
             public void testKt3563() throws Exception {
                 doTest("compiler/testData/diagnostics/tests/extensions/kt3563.kt");
@@ -2714,6 +2724,11 @@ public class JetDiagnosticsTestGenerated extends AbstractDiagnosticsTestWithEage
                 doTest("compiler/testData/diagnostics/tests/extensions/kt819ExtensionProperties.kt");
             }
             
+            @TestMetadata("noClassObjectsInJava.kt")
+            public void testNoClassObjectsInJava() throws Exception {
+                doTest("compiler/testData/diagnostics/tests/extensions/noClassObjectsInJava.kt");
+            }
+            
             @TestMetadata("object.kt")
             public void testObject() throws Exception {
                 doTest("compiler/testData/diagnostics/tests/extensions/object.kt");
diff --git a/compiler/tests/org/jetbrains/jet/codegen/generated/BlackBoxCodegenTestGenerated.java b/compiler/tests/org/jetbrains/jet/codegen/generated/BlackBoxCodegenTestGenerated.java
index 73317b40af1..0470bcdac46 100644
--- a/compiler/tests/org/jetbrains/jet/codegen/generated/BlackBoxCodegenTestGenerated.java
+++ b/compiler/tests/org/jetbrains/jet/codegen/generated/BlackBoxCodegenTestGenerated.java
@@ -743,6 +743,11 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
             doTest("compiler/testData/codegen/box/classes/classObjectNotOfEnum.kt");
         }
         
+        @TestMetadata("classObjectToString.kt")
+        public void testClassObjectToString() throws Exception {
+            doTest("compiler/testData/codegen/box/classes/classObjectToString.kt");
+        }
+        
         @TestMetadata("classObjectWithPrivateGenericMember.kt")
         public void testClassObjectWithPrivateGenericMember() throws Exception {
             doTest("compiler/testData/codegen/box/classes/classObjectWithPrivateGenericMember.kt");
diff --git a/core/descriptors/src/org/jetbrains/jet/lang/types/NamespaceType.java b/core/descriptors/src/org/jetbrains/jet/lang/types/NamespaceType.java
index be405b4ebb1..b9b60d73c47 100644
--- a/core/descriptors/src/org/jetbrains/jet/lang/types/NamespaceType.java
+++ b/core/descriptors/src/org/jetbrains/jet/lang/types/NamespaceType.java
@@ -20,6 +20,7 @@ import org.jetbrains.annotations.NotNull;
 import org.jetbrains.jet.lang.descriptors.annotations.AnnotationDescriptor;
 import org.jetbrains.jet.lang.resolve.name.Name;
 import org.jetbrains.jet.lang.resolve.scopes.JetScope;
+import org.jetbrains.jet.lang.resolve.scopes.receivers.ReceiverValue;
 
 import java.util.List;
 
@@ -29,12 +30,13 @@ import java.util.List;
  */
 public class NamespaceType implements JetType {
     private final Name name;
-    @NotNull
     private final JetScope memberScope;
+    private final ReceiverValue receiver;
 
-    public NamespaceType(@NotNull Name name, @NotNull JetScope memberScope) {
+    public NamespaceType(@NotNull Name name, @NotNull JetScope memberScope, @NotNull ReceiverValue receiver) {
         this.name = name;
         this.memberScope = memberScope;
+        this.receiver = receiver;
     }
 
     @NotNull
@@ -48,6 +50,11 @@ public class NamespaceType implements JetType {
         return false;
     }
 
+    @NotNull
+    public ReceiverValue getReceiverValue() {
+        return receiver;
+    }
+
     @NotNull
     @Override
     public TypeConstructor getConstructor() {