diff --git a/clang/lib/Interpreter/Interpreter.cpp b/clang/lib/Interpreter/Interpreter.cpp
index bf0c98785ab79..e41024a256525 100644
--- a/clang/lib/Interpreter/Interpreter.cpp
+++ b/clang/lib/Interpreter/Interpreter.cpp
@@ -540,6 +540,7 @@ class RuntimeInterfaceBuilder
           E->getBeginLoc(), Args, E->getEndLoc());
     }
     }
+    llvm_unreachable("Unhandled Interpreter::InterfaceKind");
   }
 
   Interpreter::InterfaceKind VisitRecordType(const RecordType *Ty) {