diff --git a/NPLib/Detectors/MUST2/TMust2Physics.cxx b/NPLib/Detectors/MUST2/TMust2Physics.cxx
index 467ec8142d18a9bfc8bd512d16e8646cf9ea4d29..10435fc52d3bcdb69a5f1132c4da95e69b557860 100644
--- a/NPLib/Detectors/MUST2/TMust2Physics.cxx
+++ b/NPLib/Detectors/MUST2/TMust2Physics.cxx
@@ -80,7 +80,7 @@ ClassImp(TMust2Physics)
   m_SiLi_MatchingY.resize(16, 0);
 
   m_SiLi_MatchingX[0] = 112;
-  m_SiLi_MatchingY[1] = 112;
+  m_SiLi_MatchingY[0] = 112;
 
   m_SiLi_MatchingX[1] = 112;
   m_SiLi_MatchingY[1] = 80;