diff --git a/lib/CodeGen/CGExprScalar.cpp b/lib/CodeGen/CGExprScalar.cpp
index 76c91a5..125e431 100644
--- a/lib/CodeGen/CGExprScalar.cpp
+++ b/lib/CodeGen/CGExprScalar.cpp
@@ -1149,8 +1149,7 @@
     return CGF.EmitARCExtendBlockObject(E);
 
   case CK_CopyAndAutoreleaseBlockObject:
-    CGF.ErrorUnsupported(E, "copy/autorelease block object");
-    return 0;
+    return CGF.EmitBlockCopyAndAutorelease(Visit(E), E->getType());
       
   case CK_FloatingRealToComplex:
   case CK_FloatingComplexCast:
diff --git a/lib/CodeGen/CGObjC.cpp b/lib/CodeGen/CGObjC.cpp
index 9792017..9eb58fc 100644
--- a/lib/CodeGen/CGObjC.cpp
+++ b/lib/CodeGen/CGObjC.cpp
@@ -2774,5 +2774,30 @@
   return HelperFn;
 }
 
+llvm::Value *
+CodeGenFunction::EmitBlockCopyAndAutorelease(llvm::Value *Block, QualType Ty) {
+  // Get selectors for retain/autorelease.
+  IdentifierInfo *RetainID = &getContext().Idents.get("retain");
+  Selector RetainSelector =
+      getContext().Selectors.getNullarySelector(RetainID);
+  IdentifierInfo *AutoreleaseID = &getContext().Idents.get("autorelease");
+  Selector AutoreleaseSelector =
+      getContext().Selectors.getNullarySelector(AutoreleaseID);
+
+  // Emit calls to retain/autorelease.
+  CGObjCRuntime &Runtime = CGM.getObjCRuntime();
+  llvm::Value *Val = Block;
+  RValue Result;
+  Result = Runtime.GenerateMessageSend(*this, ReturnValueSlot(),
+                                       Ty, RetainSelector,
+                                       Val, CallArgList(), 0, 0);
+  Val = Result.getScalarVal();
+  Result = Runtime.GenerateMessageSend(*this, ReturnValueSlot(),
+                                       Ty, AutoreleaseSelector,
+                                       Val, CallArgList(), 0, 0);
+  Val = Result.getScalarVal();
+  return Val;
+}
+
 
 CGObjCRuntime::~CGObjCRuntime() {}
diff --git a/lib/CodeGen/CodeGenFunction.h b/lib/CodeGen/CodeGenFunction.h
index 71f2362..42c9b7d 100644
--- a/lib/CodeGen/CodeGenFunction.h
+++ b/lib/CodeGen/CodeGenFunction.h
@@ -1345,6 +1345,7 @@
                                              const ObjCPropertyImplDecl *PID);
   llvm::Constant *GenerateObjCAtomicGetterCopyHelperFunction(
                                              const ObjCPropertyImplDecl *PID);
+  llvm::Value *EmitBlockCopyAndAutorelease(llvm::Value *Block, QualType Ty);
 
   void BuildBlockRelease(llvm::Value *DeclPtr, BlockFieldFlags flags);