diff --git a/lib/CodeGen/CodeGenFunction.cpp b/lib/CodeGen/CodeGenFunction.cpp
index eae6161..0b01259 100644
--- a/lib/CodeGen/CodeGenFunction.cpp
+++ b/lib/CodeGen/CodeGenFunction.cpp
@@ -173,7 +173,7 @@
   // FIXME: The cast here is a huge hack.
   if (CGDebugInfo *DI = getDebugInfo()) {
     DI->setLocation(StartLoc);
-    if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
+    if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(D)) {
       DI->EmitFunctionStart(CGM.getMangledName(FD), RetTy, CurFn, Builder);
     } else {
       // Just use LLVM function name.