diff --git a/lib/CodeGen/Mangle.cpp b/lib/CodeGen/Mangle.cpp
index 48445e6..973f0d1 100644
--- a/lib/CodeGen/Mangle.cpp
+++ b/lib/CodeGen/Mangle.cpp
@@ -241,7 +241,7 @@
     FD = PrimaryTemplate->getTemplatedDecl();
   }
 
-  mangleBareFunctionType(FD->getType()->getAsFunctionType(), MangleReturnType);
+  mangleBareFunctionType(FD->getType()->getAs<FunctionType>(), MangleReturnType);
 }
 
 static bool isStdNamespace(const DeclContext *DC) {