diff --git a/test/Driver/cl.c b/test/Driver/cl.c
index 1187a31..c811dbe 100644
--- a/test/Driver/cl.c
+++ b/test/Driver/cl.c
@@ -1,18 +1,22 @@
-// Note: we have to quote the options with a /, otherwise some shells will try
-// to expand it and make test fail.
+// Don't attempt slash switches on msys bash.
+// REQUIRES: shell-preserves-root
+
+// Note: we have to quote the /? option, otherwise some shells will try to
+// expand the ? into a one-letter filename in the root directory, and make
+// the test fail is such a file or directory exists.
 
 // Check that clang-cl options are not available by default.
 // RUN: %clang -help | FileCheck %s -check-prefix=DEFAULT
 // DEFAULT-NOT: CL.EXE COMPATIBILITY OPTIONS
 // DEFAULT-NOT: {{/[?]}}
 // DEFAULT-NOT: /help
-// RUN: not %clang '/?'
+// RUN: not %clang "/?"
 // RUN: not %clang -?
-// RUN: not %clang '/help'
+// RUN: not %clang /help
 
-// Check that '/?' and '/help' are available as clang-cl options.
-// RUN: %clang_cl '/?' | FileCheck %s -check-prefix=CL
-// RUN: %clang_cl '/help' | FileCheck %s -check-prefix=CL
+// Check that /? and /help are available as clang-cl options.
+// RUN: %clang_cl "/?" | FileCheck %s -check-prefix=CL
+// RUN: %clang_cl /help | FileCheck %s -check-prefix=CL
 // RUN: %clang_cl -help | FileCheck %s -check-prefix=CL
 // CL: CL.EXE COMPATIBILITY OPTIONS
 // CL: {{/[?]}}
@@ -22,6 +26,3 @@
 // are not available in clang-cl.
 // DEFAULT: -fapple-kext
 // CL-NOT: -fapple-kext
-
-// Don't attempt slash switches on msys bash.
-// REQUIRES: shell-preserves-root