diff --git a/clang/test/Sema/no-warn-missing-prototype.c b/clang/test/Sema/no-warn-missing-prototype.c
index 2361677a5f73..4dbc25755922 100644
--- a/clang/test/Sema/no-warn-missing-prototype.c
+++ b/clang/test/Sema/no-warn-missing-prototype.c
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -fsyntax-only -Wmissing-prototypes-x c -ffreestanding -verify %s
+// RUN: %clang_cc1 -fsyntax-only -Wmissing-prototypes -x c -ffreestanding -verify %s
 // RUN: %clang_cc1 -fsyntax-only -Wmissing-prototypes -x c++ -ffreestanding -verify %s
 // expected-no-diagnostics
 int main() {