diff --git a/MuonSpectrometer/MuonDetDescr/MuonReadoutGeometry/MuonReadoutGeometry/MMReadoutElement.h b/MuonSpectrometer/MuonDetDescr/MuonReadoutGeometry/MuonReadoutGeometry/MMReadoutElement.h
index 3c9eaee67edabf49d4967a5f5008f928c71e16d3..b3d9b9aa0970d82ec256dd91b2a49308b5062ae1 100644
--- a/MuonSpectrometer/MuonDetDescr/MuonReadoutGeometry/MuonReadoutGeometry/MMReadoutElement.h
+++ b/MuonSpectrometer/MuonDetDescr/MuonReadoutGeometry/MuonReadoutGeometry/MMReadoutElement.h
@@ -286,12 +286,13 @@ namespace MuonGM {
         // Get the nearest strip number; not the time yet to check boundaries (in case of tolerance) 
         int stripNo = stripNumber(locpos, id);
         if (stripNo < 0) stripNo = (locpos.x()<0) ? 1 : design->totalStrips;
+        Identifier channelId = manager()->mmIdHelper()->channelID(id, m_ml, manager()->mmIdHelper()->gasGap(id), stripNo);
 
         // ** Horizontal passivation: mask entire strips
         //==============================================
         int pcb      = (stripNo-1)/1024 + 1; // starts from 1
         int pcbStrip = stripNo - 1024*(pcb - 1);
-        PCBPassivation pcbPassiv = m_passivData ? m_passivData->getPassivation(id) :s_dummy_passiv;
+        PCBPassivation pcbPassiv = m_passivData ? m_passivData->getPassivation(channelId) :s_dummy_passiv;
         // if(m_passivData && !pcbPassiv.valid) return false;
         // the passivated width is constant along the PCB edge (not along y for stereo strips)
         if(pcb != 1) pcbPassiv.bottom /= std::cos(design->sAngle);