diff --git a/clang/test/utils/update_cc_test_checks/lit.local.cfg b/clang/test/utils/update_cc_test_checks/lit.local.cfg
--- a/clang/test/utils/update_cc_test_checks/lit.local.cfg
+++ b/clang/test/utils/update_cc_test_checks/lit.local.cfg
@@ -1,4 +1,5 @@
 import os
+import glob
 
 import lit.util
 
@@ -19,7 +20,9 @@
 script_path = os.path.join(config.llvm_src_root, 'utils',
                            'update_cc_test_checks.py')
 assert os.path.isfile(script_path)
-lit = config.llvm_external_lit if config.llvm_external_lit else shell_quote(os.path.join(config.llvm_src_root, 'utils', 'lit', 'lit.py'))
+# Windows: llvm-lit.py, Linux: llvm-lit
+llvm_lit = glob.glob(os.path.join(config.llvm_tools_dir, 'llvm-lit*'))[0]
+lit = config.llvm_external_lit if config.llvm_external_lit else shell_quote(llvm_lit)
 python = shell_quote(config.python_executable)
 config.substitutions.append(
     ('%update_cc_test_checks', "%s %s %s" % (