diff --git a/tests/unit/config/test_configexc.py b/tests/unit/config/test_configexc.py
index a6c02f72e..5da3837c1 100644
--- a/tests/unit/config/test_configexc.py
+++ b/tests/unit/config/test_configexc.py
@@ -38,3 +38,9 @@ def test_no_option_error():
 def test_backend_error():
     e = configexc.BackendError(usertypes.Backend.QtWebKit)
     assert str(e) == "This setting is not available with the QtWebKit backend!"
+
+
+def test_duplicate_key_error():
+    e = configexc.DuplicateKeyError('asdf')
+    assert isinstance(e, configexc.KeybindingError)
+    assert str(e) == "Duplicate key asdf"