diff --git a/datasalad/settings/env.py b/datasalad/settings/env.py
index 5d96e46..593a096 100644
--- a/datasalad/settings/env.py
+++ b/datasalad/settings/env.py
@@ -91,6 +91,12 @@ def keys(self) -> Collection:
     def __str__(self):
         return f'Environment[{self._var_prefix}]' if self._var_prefix else 'Environment'
 
+    def __contains__(self, key: str) -> bool:
+        # we only need to reimplement this due to Python's behavior to
+        # forece-modify environment variable names on Windows. Only
+        # talking directly for environ accounts for that
+        return key in environ
+
     def __repr__(self):
         # TODO: list keys?
         return 'Environment()'