diff --git a/src/spikeinterface/qualitymetrics/tests/test_quality_metric_calculator.py b/src/spikeinterface/qualitymetrics/tests/test_quality_metric_calculator.py
index 33cb84c5ed..cff8d88cca 100644
--- a/src/spikeinterface/qualitymetrics/tests/test_quality_metric_calculator.py
+++ b/src/spikeinterface/qualitymetrics/tests/test_quality_metric_calculator.py
@@ -76,7 +76,7 @@ def test_merging_quality_metrics(sorting_analyzer_simple):
     assert np.float64 == new_metrics["snr"].dtype
 
     # test that we appropriate convert int based metrics to int
-    assert np.int32 == new_metrics['num_spikes'].dtype
+    assert np.int32 == new_metrics["num_spikes"].dtype
 
 
 def test_compute_quality_metrics_recordingless(sorting_analyzer_simple):