Index: cfe/trunk/lib/Sema/SemaExprCXX.cpp
===================================================================
--- cfe/trunk/lib/Sema/SemaExprCXX.cpp
+++ cfe/trunk/lib/Sema/SemaExprCXX.cpp
@@ -4720,10 +4720,24 @@
     // regard to cv-qualifiers.
 
     const RecordType *lhsRecord = LhsT->getAs<RecordType>();
-    if (!lhsRecord) return false;
-
     const RecordType *rhsRecord = RhsT->getAs<RecordType>();
-    if (!rhsRecord) return false;
+    if (!rhsRecord || !lhsRecord) {
+      const ObjCObjectType *LHSObjTy = LhsT->getAs<ObjCObjectType>();
+      const ObjCObjectType *RHSObjTy = RhsT->getAs<ObjCObjectType>();
+      if (!LHSObjTy || !RHSObjTy)
+        return false;
+
+      ObjCInterfaceDecl *BaseInterface = LHSObjTy->getInterface();
+      ObjCInterfaceDecl *DerivedInterface = RHSObjTy->getInterface();
+      if (!BaseInterface || !DerivedInterface)
+        return false;
+
+      if (Self.RequireCompleteType(
+              KeyLoc, RhsT, diag::err_incomplete_type_used_in_type_trait_expr))
+        return false;
+
+      return BaseInterface->isSuperClassOf(DerivedInterface);
+    }
 
     assert(Self.Context.hasSameUnqualifiedType(LhsT, RhsT)
              == (lhsRecord == rhsRecord));
Index: cfe/trunk/test/SemaObjCXX/is-base-of.mm
===================================================================
--- cfe/trunk/test/SemaObjCXX/is-base-of.mm
+++ cfe/trunk/test/SemaObjCXX/is-base-of.mm
@@ -0,0 +1,25 @@
+// RUN: %clang_cc1 -std=c++11 -fsyntax-only -verify %s
+
+@interface NSObj
+@end
+
+@interface NSChild : NSObj
+@end
+
+static_assert(__is_base_of(NSObj, NSChild), "");
+static_assert(!__is_base_of(NSChild, NSObj), "");
+
+static_assert(__is_base_of(NSObj, NSObj), "");
+
+static_assert(!__is_base_of(NSObj *, NSChild *), "");
+static_assert(!__is_base_of(NSChild *, NSObj *), "");
+
+static_assert(__is_base_of(const volatile NSObj, NSChild), "");
+static_assert(__is_base_of(NSObj, const volatile NSChild), "");
+
+@class NSForward; // expected-note{{forward declaration of class}}
+
+static_assert(!__is_base_of(NSForward, NSObj), "");
+static_assert(!__is_base_of(NSObj, NSForward), ""); // expected-error{{incomplete type 'NSForward'}}
+
+static_assert(!__is_base_of(id, NSObj), "");