diff --git a/llvm/utils/lit/TestingConfig.py b/llvm/utils/lit/TestingConfig.py
index e4874d7a82ef7608f7e108346b876a250f6086d8..1f5067c8e50294f85434e143f80e256b4db67175 100644
--- a/llvm/utils/lit/TestingConfig.py
+++ b/llvm/utils/lit/TestingConfig.py
@@ -12,6 +12,7 @@ class TestingConfig:
             environment = {
                 'PATH' : os.pathsep.join(litConfig.path +
                                          [os.environ.get('PATH','')]),
+                'PATHEXT' : os.environ.get('PATHEXT',''),
                 'SYSTEMROOT' : os.environ.get('SYSTEMROOT',''),
                 'LLVM_DISABLE_CRT_DEBUG' : '1',
                 }