diff --git a/src/spikeinterface/extractors/cellexplorersortingextractor.py b/src/spikeinterface/extractors/cellexplorersortingextractor.py
index 0096a40a79..0980e89f1c 100644
--- a/src/spikeinterface/extractors/cellexplorersortingextractor.py
+++ b/src/spikeinterface/extractors/cellexplorersortingextractor.py
@@ -118,7 +118,6 @@ def __init__(
         spike_times = spikes_data["times"]
 
         # CellExplorer reports spike times in units seconds; SpikeExtractors uses time units of sampling frames
-        unit_ids = unit_ids[:].astype(int).tolist()
         unit_ids = [str(unit_id) for unit_id in unit_ids]
         spiketrains_dict = {unit_id: spike_times[index] for index, unit_id in enumerate(unit_ids)}
         for unit_id in unit_ids: