diff --git a/DataFormats/simulation/include/SimulationDataFormat/O2DatabasePDG.h b/DataFormats/simulation/include/SimulationDataFormat/O2DatabasePDG.h
index b9aa910652869..bd2f81f6a0338 100644
--- a/DataFormats/simulation/include/SimulationDataFormat/O2DatabasePDG.h
+++ b/DataFormats/simulation/include/SimulationDataFormat/O2DatabasePDG.h
@@ -589,9 +589,7 @@ inline void O2DatabasePDG::addALICEParticles(TDatabasePDG* db)
   if (!db->GetParticle(ionCode)) {
     db->AddParticle("Omega_Minus_2012", "Omega_Minus_2012", 2.0125, kFALSE, 0.0064, -3, "Resonance", ionCode);
   }
-  if (!db->GetParticle(-ionCode)) {
-    db->AddParticle("Omega_Plus_2012", "Omega_Plus_2012", 2.0125, kFALSE, 0.0064, 3, "Resonance", -ionCode);
-  }
+  db->AddAntiParticle("Omega_Plus_2012", -ionCode);
 
   // Ps - hidden strange (s-sbar) pentaquarks
 
diff --git a/Steer/src/O2MCApplication.cxx b/Steer/src/O2MCApplication.cxx
index dba61328c2d9c..a834b4a21c98d 100644
--- a/Steer/src/O2MCApplication.cxx
+++ b/Steer/src/O2MCApplication.cxx
@@ -646,17 +646,17 @@ void addSpecialParticles()
     psratio[j] = 0.;
   }
 
-  TVirtualMC::GetMC()->DefineParticle(3335, "Omega2012", kPTHadron, 2.012, -1.0, 1.0285e-22, "Hadron", 0.0064, 3, -1, 0, 0, 0, 0, 0, 1, kTRUE);
+  TVirtualMC::GetMC()->DefineParticle(123334, "Omega_Minus_2012", kPTHadron, 2.0125, -1.0, 1.0285e-22, "Hadron", 0.0064, 3, -1, 0, 0, 0, 0, 0, 1, kTRUE);
   psmode[0][0] = 3312; // Xi-
   psmode[0][1] = 310;  // K0S
   psratio[0] = 100.;
-  TVirtualMC::GetMC()->SetDecayMode(3335, psratio, psmode);
+  TVirtualMC::GetMC()->SetDecayMode(123334, psratio, psmode);
 
-  TVirtualMC::GetMC()->DefineParticle(-3335, "AntiOmega2012", kPTHadron, 2.012, 1.0, 1.0285e-22, "Hadron", 0.0064, 3, 1, 0, 0, 0, 0, 0, -1, kTRUE);
+  TVirtualMC::GetMC()->DefineParticle(-123334, "Omega_Plus_2012", kPTHadron, 2.0125, 1.0, 1.0285e-22, "Hadron", 0.0064, 3, 1, 0, 0, 0, 0, 0, -1, kTRUE);
   psmode[0][0] = -3312; // anti-Xi+
   psmode[0][1] = 310;   // K0S
   psratio[0] = 100.;
-  TVirtualMC::GetMC()->SetDecayMode(-3335, psratio, psmode);
+  TVirtualMC::GetMC()->SetDecayMode(-123334, psratio, psmode);
 
   // d*(2380) - dibaryon resonance
   TVirtualMC::GetMC()->DefineParticle(900010020, "d*_2380", kPTHadron, 2.38, 1.0, 0.94e-23, "Ion", 0.07, 6, 1, 0, 0, 0, 0, 0, 2, kTRUE);