diff --git a/src/spikeinterface/qualitymetrics/quality_metric_calculator.py b/src/spikeinterface/qualitymetrics/quality_metric_calculator.py
index 8a754fc7da..52eb56c4ee 100644
--- a/src/spikeinterface/qualitymetrics/quality_metric_calculator.py
+++ b/src/spikeinterface/qualitymetrics/quality_metric_calculator.py
@@ -165,7 +165,7 @@ def _compute_metrics(self, sorting_analyzer, unit_ids=None, verbose=False, metri
 
         import pandas as pd
 
-        metrics = pd.DataFrame(index=sorting_analyzer.unit_ids)
+        metrics = pd.DataFrame(index=unit_ids)
 
         # simple metrics not based on PCs
         for metric_name in metric_names: