diff --git a/tests/test_dxvk_config_defaults.py b/tests/test_dxvk_config_defaults.py
new file mode 100644
index 0000000..408d25f
--- /dev/null
+++ b/tests/test_dxvk_config_defaults.py
@@ -0,0 +1,24 @@
+import os
+import unittest
+
+
+class DxvkConfigDefaultsTests(unittest.TestCase):
+    def test_exclusive_fullscreen_is_disabled_by_default(self):
+        repo_root = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+        config_path = os.path.join(repo_root, "Payload", "dxvk.conf")
+
+        with open(config_path, "r", encoding="utf-8") as handle:
+            active_settings = [
+                line.strip()
+                for line in handle
+                if line.strip() and not line.lstrip().startswith("#")
+            ]
+
+        allow_fse_settings = [
+            line for line in active_settings if line.lower().startswith("dxvk.allowfse")
+        ]
+        self.assertEqual(allow_fse_settings, ["dxvk.allowFse = False"])
+
+
+if __name__ == "__main__":
+    unittest.main()