diff --git a/utils/lit/lit/TestingConfig.py b/utils/lit/lit/TestingConfig.py
index 4a34b77e175..95405e93244 100644
--- a/utils/lit/lit/TestingConfig.py
+++ b/utils/lit/lit/TestingConfig.py
@@ -38,7 +38,7 @@ class TestingConfig:
         # The option to preserve TEMP, TMP, and TMPDIR.
         # This is intended to check how many temporary files would be generated
         # (and be not cleaned up) in automated builders.
-        if os.environ.has_key('LIT_PRESERVES_TMP'):
+        if 'LIT_PRESERVES_TMP' in os.environ:
             environment.update({
                     'TEMP' : os.environ.get('TEMP',''),
                     'TMP' : os.environ.get('TMP',''),