diff --git a/lib/CodeGen/CGBlocks.cpp b/lib/CodeGen/CGBlocks.cpp
index 703615a..da7afe1 100644
--- a/lib/CodeGen/CGBlocks.cpp
+++ b/lib/CodeGen/CGBlocks.cpp
@@ -223,6 +223,10 @@
     Elts.push_back(BuildDescriptorBlockDecl(subBlockSize));
 
     if (subBlockDeclRefDecls.size() == 0) {
+      // Optimize to being a global block.
+      Elts[0] = CGM.getNSConcreteGlobalBlock();
+      Elts[1] = llvm::ConstantInt::get(IntTy, flags|BLOCK_IS_GLOBAL);
+
       C = llvm::ConstantStruct::get(Elts);
 
       char Name[32];