diff --git a/clang/lib/Serialization/ASTCommon.cpp b/clang/lib/Serialization/ASTCommon.cpp
index 67f74f7..0ec03cf 100644
--- a/clang/lib/Serialization/ASTCommon.cpp
+++ b/clang/lib/Serialization/ASTCommon.cpp
@@ -60,6 +60,9 @@
   case BuiltinType::ObjCId:     ID = PREDEF_TYPE_OBJC_ID;       break;
   case BuiltinType::ObjCClass:  ID = PREDEF_TYPE_OBJC_CLASS;    break;
   case BuiltinType::ObjCSel:    ID = PREDEF_TYPE_OBJC_SEL;      break;
+  case BuiltinType::BuiltinFn:
+                                ID = PREDEF_TYPE_BUILTIN_FN; break;
+
   }
 
   return TypeIdx(ID);