diff --git a/test/Modules/warn-unused-local-typedef.cpp b/test/Modules/warn-unused-local-typedef.cpp
index a463621d4ef582a750ab64706bf36e94a0cd1743..60e0612d6ce7840564dfd54f32ab466388cacf33 100644
--- a/test/Modules/warn-unused-local-typedef.cpp
+++ b/test/Modules/warn-unused-local-typedef.cpp
@@ -1,6 +1,6 @@
 // RUN: rm -rf %t
-// RUN: %clang -Wunused-local-typedef -c -x objective-c++ -fcxx-modules -fmodules -fmodules-cache-path=%t -I %S/Inputs %s 2>&1 | FileCheck %s -check-prefix=CHECK_1
-// RUN: %clang -Wunused-local-typedef -c -x objective-c++ -fcxx-modules -fmodules -fmodules-cache-path=%t -I %S/Inputs %s 2>&1 | FileCheck %s -check-prefix=CHECK_2 -allow-empty
+// RUN: %clang -Wunused-local-typedef -c -x objective-c++ -fcxx-modules -fmodules -fmodules-cache-path=%t -I %S/Inputs %s -o /dev/null 2>&1 | FileCheck %s -check-prefix=CHECK_1
+// RUN: %clang -Wunused-local-typedef -c -x objective-c++ -fcxx-modules -fmodules -fmodules-cache-path=%t -I %S/Inputs %s -o /dev/null 2>&1 | FileCheck %s -check-prefix=CHECK_2 -allow-empty
 
 // For modules, the warning should only fire the first time, when the module is
 // built.