diff --git a/tests/test_error_handler.py b/tests/test_error_handler.py
index 9a8773b2..c2ff7ba4 100644
--- a/tests/test_error_handler.py
+++ b/tests/test_error_handler.py
@@ -24,4 +24,4 @@ def test_catch():
     with patch('ipwb.error_handler.logger.critical', mock_logger):
         caught_error('boo')
 
-    mock_logger.assert_called_with('boo')
+    mock_logger.assert_called_once('boo')