diff --git a/test/tools/llvm-profdata/invalid-profdata.test b/test/tools/llvm-profdata/invalid-profdata.test
index b6391b03464..4d6936f8a32 100644
--- a/test/tools/llvm-profdata/invalid-profdata.test
+++ b/test/tools/llvm-profdata/invalid-profdata.test
@@ -20,7 +20,7 @@ RUN: echo "f2:0"                                         >> %t.input
 RUN: echo "1"                                            >> %t.input
 RUN: echo ":10"                                          >> %t.input
 
-RUN: not llvm-profdata merge %t.input -text -output=/dev/null 2>&1  | FileCheck %s --check-prefix=BROKEN
+RUN: not llvm-profdata merge %t.input -text -o /dev/null 2>&1  | FileCheck %s --check-prefix=BROKEN
 BROKEN: Malformed instrumentation profile data
 
 RUN: echo ":ir"                     > %t.input
diff --git a/utils/lit/lit/TestRunner.py b/utils/lit/lit/TestRunner.py
index a2031757d8b..93d5c5ba039 100644
--- a/utils/lit/lit/TestRunner.py
+++ b/utils/lit/lit/TestRunner.py
@@ -36,7 +36,6 @@ kUseCloseFDs = not kIsWindows
 
 # Use temporary files to replace /dev/null on Windows.
 kAvoidDevNull = kIsWindows
-kDevNull = "/dev/null"
 
 class ShellEnvironment(object):
 
@@ -627,7 +626,7 @@ def processRedirects(cmd, stdin_source, cmd_shenv, opened_files):
            raise InternalShellError(cmd, "Unsupported: glob in "
                                     "redirect expanded to multiple files")
         name = name[0]
-        if kAvoidDevNull and name == kDevNull:
+        if kAvoidDevNull and name == '/dev/null':
             fd = tempfile.TemporaryFile(mode=mode)
         elif kIsWindows and name == '/dev/tty':
             # Simulate /dev/tty on Windows.
@@ -798,11 +797,11 @@ def _executeShCmd(cmd, shenv, results, timeoutHelper):
         # Replace uses of /dev/null with temporary files.
         if kAvoidDevNull:
             for i,arg in enumerate(args):
-                if kDevNull in arg:
+                if arg == "/dev/null":
                     f = tempfile.NamedTemporaryFile(delete=False)
                     f.close()
                     named_temp_files.append(f.name)
-                    args[i] = arg.replace(kDevNull, f.name)
+                    args[i] = f.name
 
         # Expand all glob expressions
         args = expand_glob_expressions(args, cmd_shenv.cwd)
diff --git a/utils/lit/tests/Inputs/shtest-shell/check_args.py b/utils/lit/tests/Inputs/shtest-shell/check_args.py
deleted file mode 100644
index 2f7a2503b97..00000000000
--- a/utils/lit/tests/Inputs/shtest-shell/check_args.py
+++ /dev/null
@@ -1,14 +0,0 @@
-#!/usr/bin/env python
-
-import argparse
-import platform
-
-parser = argparse.ArgumentParser()
-parser.add_argument("--my_arg", "-a")
-
-args = parser.parse_args()
-
-answer = (platform.system() == "Windows" and
-          args.my_arg == "/dev/null" and "ERROR") or "OK"
-
-print(answer)
diff --git a/utils/lit/tests/Inputs/shtest-shell/dev-null.txt b/utils/lit/tests/Inputs/shtest-shell/dev-null.txt
deleted file mode 100644
index 5b742489cc8..00000000000
--- a/utils/lit/tests/Inputs/shtest-shell/dev-null.txt
+++ /dev/null
@@ -1,14 +0,0 @@
-# Check handling of /dev/null in command line options
-# On windows, it should be redirected to a temp file.
-#
-# RUN: "%{python}" %S/check_args.py --my_arg /dev/null | FileCheck %s --check-prefix=CHECK1
-# CHECK1: OK
-
-# RUN: "%{python}" %S/check_args.py --my_arg=/dev/null | FileCheck %s --check-prefix=CHECK2
-# CHECK2: OK
-
-# RUN: "%{python}" %S/check_args.py -a /dev/null | FileCheck %s --check-prefix=CHECK3
-# CHECK3: OK
-
-# RUN: "%{python}" %S/check_args.py -a=/dev/null | FileCheck %s --check-prefix=CHECK4
-# CHECK4: OK