diff --git a/clang/include/clang/AST/TypeProperties.td b/clang/include/clang/AST/TypeProperties.td
index 8fa4e4bc1bcbb1..caa5835911c5d8 100644
--- a/clang/include/clang/AST/TypeProperties.td
+++ b/clang/include/clang/AST/TypeProperties.td
@@ -691,6 +691,7 @@ let Class = BuiltinType in {
 
 	def : Creator<[{
 		switch (kind) {
+        default: llvm_unreachable("unreachable builtin case");
 #define IMAGE_TYPE(IMGTYPE, ID, SINGLETON_ID, ACCESS, SUFFIX) \
 		case BuiltinType::ID: return ctx.SINGLETON_ID;
 #include "clang/Basic/OpenCLImageTypes.def"