diff --git a/llvm/utils/lit/lit/llvm/config.py b/llvm/utils/lit/lit/llvm/config.py
--- a/llvm/utils/lit/lit/llvm/config.py
+++ b/llvm/utils/lit/lit/llvm/config.py
@@ -4,6 +4,7 @@
 import re
 import subprocess
 import sys
+import errno
 
 import lit.util
 from lit.llvm.subst import FindTool
@@ -346,21 +347,10 @@
         return True
 
     def add_err_msg_substitutions(self):
-        if (sys.platform == 'zos'):
-            self.config.substitutions.append(('%errc_ENOENT', '\'EDC5129I No such file or directory.\''))
-            self.config.substitutions.append(('%errc_EISDIR', '\'EDC5123I Is a directory.\''))
-            self.config.substitutions.append(('%errc_EINVAL', '\'EDC5121I Invalid argument.\''))
-            self.config.substitutions.append(('%errc_EACCES', '\'EDC5111I Permission denied.\''))
-        elif (sys.platform == 'win32'):
-            self.config.substitutions.append(('%errc_ENOENT', '\'no such file or directory\''))
-            self.config.substitutions.append(('%errc_EISDIR', '\'is a directory\''))
-            self.config.substitutions.append(('%errc_EINVAL', '\'invalid argument\''))
-            self.config.substitutions.append(('%errc_EACCES', '\'permission denied\''))
-        else:
-            self.config.substitutions.append(('%errc_ENOENT', '\'No such file or directory\''))
-            self.config.substitutions.append(('%errc_EISDIR', '\'Is a directory\''))
-            self.config.substitutions.append(('%errc_EINVAL', '\'Invalid argument\''))
-            self.config.substitutions.append(('%errc_EACCES', '\'Permission denied\''))
+        self.config.substitutions.append(('%errc_ENOENT', '\'' + os.strerror(errno.ENOENT) + '\''))
+        self.config.substitutions.append(('%errc_EISDIR', '\'' + os.strerror(errno.EISDIR) + '\''))
+        self.config.substitutions.append(('%errc_EINVAL', '\'' + os.strerror(errno.EINVAL) + '\''))
+        self.config.substitutions.append(('%errc_EACCES', '\'' + os.strerror(errno.EACCES) + '\''))
 
     def use_default_substitutions(self):
         tool_patterns = [