diff --git a/clang/test/Driver/as-options.s b/clang/test/Driver/as-options.s
index 72e9153f5a58..956f07ac0f21 100644
--- a/clang/test/Driver/as-options.s
+++ b/clang/test/Driver/as-options.s
@@ -73,7 +73,7 @@
 
 // -Wa flags shouldn't cause warnings without an assembler stage with
 // -fno-integrated-as either.
-// RUN: %clang -Wa,-mno-warn-deprecated -fno-integrated-as %s -S 2>&1 \
+// RUN: %clang -Wa,-mno-warn-deprecated -fno-integrated-as -x c++ %s -S 2>&1 \
 // RUN:   | FileCheck --check-prefix=NOWARN --allow-empty %s
 
 // But -m flags for the integrated assembler _should_ warn if the integrated