diff --git a/legendary/core.py b/legendary/core.py
index 89d9bf8..7de4d20 100644
--- a/legendary/core.py
+++ b/legendary/core.py
@@ -1703,6 +1703,8 @@ class LegendaryCore:
         self.overlay_update_available = version_info['buildVersion'] != installed.version
 
     def is_overlay_installed(self):
+        if os.name != 'nt':
+            return False
         return self.lgd.get_overlay_install_info() is not None
 
     @staticmethod