diff --git a/src/spikeinterface/core/node_pipeline.py b/src/spikeinterface/core/node_pipeline.py
index 609d55fa6d..afe2e1e4ca 100644
--- a/src/spikeinterface/core/node_pipeline.py
+++ b/src/spikeinterface/core/node_pipeline.py
@@ -97,7 +97,7 @@ def _first_call_before_pipeline(self):
         # see need_first_call_before_pipeline = True
         margin = self.get_margin()
         traces = self.recording.get_traces(start_frame=0, end_frame=margin * 2 + 1, segment_index=0)
-        self.compute(traces, 0, margin * 2 + 1, 0, margin)
+        self.compute(traces, margin, margin + 1, 0, margin)
 
 
 # this is used in sorting components