diff --git a/Lib/test/test_webbrowser.py b/Lib/test/test_webbrowser.py
index 51d627d24c5a8a..82f14ca968f266 100644
--- a/Lib/test/test_webbrowser.py
+++ b/Lib/test/test_webbrowser.py
@@ -340,6 +340,10 @@ def close(self):
 @requires_subprocess()
 class MacOSTest(unittest.TestCase):
 
+    def setUp(self):
+        env = self.enterContext(os_helper.EnvironmentVarGuard())
+        env.unset("BROWSER")
+
     def test_default(self):
         browser = webbrowser.get()
         self.assertIsInstance(browser, webbrowser.MacOS)