diff --git a/compiler/backend/src/org/jetbrains/jet/codegen/JetTypeMapper.java b/compiler/backend/src/org/jetbrains/jet/codegen/JetTypeMapper.java
index 70dd53b2527..ef2cef70364 100644
--- a/compiler/backend/src/org/jetbrains/jet/codegen/JetTypeMapper.java
+++ b/compiler/backend/src/org/jetbrains/jet/codegen/JetTypeMapper.java
@@ -550,9 +550,6 @@ public class JetTypeMapper {
             signatureVisitor.writeClassBound();
 
             for (JetType jetType : typeParameterDescriptor.getUpperBounds()) {
-                if (jetType.equals(JetStandardClasses.getNullableAnyType())) {
-                    continue;
-                }
                 if (jetType.getConstructor().getDeclarationDescriptor() instanceof ClassDescriptor) {
                     if (!CodegenUtil.isInterface(jetType)) {
                         mapType(jetType, signatureVisitor);
@@ -561,7 +558,10 @@ public class JetTypeMapper {
                 }
             }
 
-            // "extends Object" seems to be not optional according to ClassFileFormat-Java5.pdf
+            // "extends Object" is optional according to ClassFileFormat-Java5.pdf
+            // but javac complaints to signature:
+            // <P:>Ljava/lang/Object;
+            // TODO: avoid writing java/lang/Object if interface list is not empty
         }
         signatureVisitor.writeClassBoundEnd();
 
diff --git a/compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/JavaDescriptorResolver.java b/compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/JavaDescriptorResolver.java
index 13edfab638f..d5a4365ce9d 100644
--- a/compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/JavaDescriptorResolver.java
+++ b/compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/JavaDescriptorResolver.java
@@ -252,6 +252,23 @@ public class JavaDescriptorResolver {
         throw new IllegalStateException("PsiTypeParameter '" + name + "' is not found");
     }
 
+
+    // cache
+    protected ClassDescriptor javaLangObject;
+
+    @NotNull
+    private ClassDescriptor getJavaLangObject() {
+        if (javaLangObject == null) {
+            javaLangObject = resolveClass("java.lang.Object");
+        }
+        return javaLangObject;
+    }
+
+    private boolean isJavaLangObject(JetType type) {
+        return type.getConstructor().getDeclarationDescriptor() == getJavaLangObject();
+    }
+
+
     private abstract class JetSignatureTypeParameterVisitor extends JetSignatureExceptionsAdapter {
         
         private final DeclarationDescriptor containingDeclaration;
@@ -272,12 +289,15 @@ public class JavaDescriptorResolver {
 
         List<JetType> upperBounds = new ArrayList<JetType>();
         List<JetType> lowerBounds = new ArrayList<JetType>();
-
+        
         @Override
         public JetSignatureVisitor visitClassBound() {
             return new JetTypeJetSignatureReader(JavaDescriptorResolver.this, semanticServices.getJetSemanticServices().getStandardLibrary()) {
                 @Override
                 protected void done(@NotNull JetType jetType) {
+                    if (isJavaLangObject(jetType)) {
+                        return;
+                    }
                     upperBounds.add(jetType);
                 }
             };