diff --git a/lib/CodeGen/CodeGenModule.cpp b/lib/CodeGen/CodeGenModule.cpp
index 8a88051..0759abd 100644
--- a/lib/CodeGen/CodeGenModule.cpp
+++ b/lib/CodeGen/CodeGenModule.cpp
@@ -286,6 +286,9 @@
 
   if (D->getAttr<StdCallAttr>())
     F->setCallingConv(llvm::CallingConv::X86_StdCall);
+
+  if (D->getAttr<RegparmAttr>())
+    ErrorUnsupported(D, "regparm attribute");
 }
 
 /// SetFunctionAttributesForDefinition - Set function attributes
@@ -308,6 +311,9 @@
   
   if (D->getAttr<NoinlineAttr>())
     F->addFnAttr(llvm::Attribute::NoInline);
+  
+  if (D->getAttr<RegparmAttr>())
+    ErrorUnsupported(D, "regparm attribute");
 }
 
 void CodeGenModule::SetMethodAttributes(const ObjCMethodDecl *MD,