diff --git a/rtv/objects.py b/rtv/objects.py
index 7113a82..64116df 100644
--- a/rtv/objects.py
+++ b/rtv/objects.py
@@ -42,7 +42,11 @@ def patch_webbrowser():
             for cmdline in reversed(_userchoices):
                 if cmdline in ('safari', 'firefox', 'chrome', 'default'):
                     browser = webbrowser.MacOSXOSAScript(cmdline)
-                    webbrowser.register(cmdline, None, browser, -1)
+                    try:
+                        webbrowser.register(cmdline, None, browser, update_tryorder=-1)
+                    except AttributeError:
+                        # 3.7 nightly build changed the method signature
+                        webbrowser.register(cmdline, None, browser, preferred=True)
 
 
 @contextmanager
diff --git a/tests/test_objects.py b/tests/test_objects.py
index 31b0c30..3d797a8 100644
--- a/tests/test_objects.py
+++ b/tests/test_objects.py
@@ -20,11 +20,16 @@ try:
 except ImportError:
     import mock
 
+# webbrowser's command to check if a file exists is different for py2/py3
+if six.PY3:
+    mock_isfile = mock.patch('shutil.which', return_value=None)
+else:
+    mock_isfile = mock.patch('os.path.isfile', return_value=None)
+
 
 @mock.patch.dict(os.environ, {'BROWSER': 'safari'})
 @mock.patch('sys.platform', 'darwin')
-@mock.patch('shutil.which', return_value=None)    # py3 method
-@mock.patch('os.path.isfile', return_value=None)  # py2 method
+@mock_isfile
 def test_patch_webbrowser(which, isfile):
 
     # Make sure that webbrowser re-generates the browser list using the