From 7793cb15c43f54a45eea3af74945da7164946e7c Mon Sep 17 00:00:00 2001
From: marcellocosti <marcellodicostanzo00@gmail.com>
Date: Mon, 7 Sep 2026 11:43:49 +0200
Subject: [PATCH] Fix back-propagation of hit in stepping

---
 Detectors/Upgrades/ALICE3/IOTOF/simulation/src/Digitizer.cxx | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Detectors/Upgrades/ALICE3/IOTOF/simulation/src/Digitizer.cxx b/Detectors/Upgrades/ALICE3/IOTOF/simulation/src/Digitizer.cxx
index 5de01639312c4..2cac7e471df19 100644
--- a/Detectors/Upgrades/ALICE3/IOTOF/simulation/src/Digitizer.cxx
+++ b/Detectors/Upgrades/ALICE3/IOTOF/simulation/src/Digitizer.cxx
@@ -194,7 +194,7 @@ void Digitizer::stepping(const o2::itsmft::Hit& hit, float**& respMatrix, int& r
       LOG(debug) << "Hit position out of bounds for detector ID " << chipID;
       return; // hit is outside the active area
     }
-    xyzPositionEnd += stepVector;
+    xyzPositionEnd -= stepVector;
   }
 
   if (rowStart > rowEnd) {