diff --git a/keyring/testing/backend.py b/keyring/testing/backend.py
index ac9ad6de..6c6628b9 100644
--- a/keyring/testing/backend.py
+++ b/keyring/testing/backend.py
@@ -163,6 +163,10 @@ def test_credential(self):
             ('user2', 'password2'),
         )
 
+    def test_empty_username(self):
+        self.set_password('service1', '', 'password1')
+        assert self.keyring.get_password('service1', '') == 'password1'
+
     def test_set_properties(self, monkeypatch):
         env = dict(KEYRING_PROPERTY_FOO_BAR='fizz buzz', OTHER_SETTING='ignore me')
         monkeypatch.setattr(os, 'environ', env)