diff --git a/MC/config/examples/epos4/generator_EPOS4.C b/MC/config/examples/epos4/generator_EPOS4.C
index 6d08a7b19..1dd5cd3fd 100644
--- a/MC/config/examples/epos4/generator_EPOS4.C
+++ b/MC/config/examples/epos4/generator_EPOS4.C
@@ -43,19 +43,26 @@ FairGenerator* generateEPOS4(const std::string &name, const int& nEvents)
         buffer << line << "\n";
     }
     file.close();
+    auto gen = new GeneratorEPOS4();
+    auto &param0 = o2::eventgen::GeneratorFileOrCmdParam::Instance();
+    auto &param = o2::eventgen::GeneratorHepMCParam::Instance();
+    auto &conf = o2::conf::SimConfig::Instance();
+    // Randomise seed (useful for multiple instances of the generator)
+    int randomSeed = gRandom->Integer(conf.getStartSeed());
     // Write the updated content back to a file in the current directory
-    std::ofstream outFile("cfg.optns");
+    std::string optnsFileName(Form("cfg%d.optns", randomSeed));
+    std::ofstream outFile(optnsFileName);
     outFile << buffer.str();
     if (!found)
     {
         outFile << "set nfull " + std::to_string(nEvents);
     }
     outFile.close();
-    auto gen = new GeneratorEPOS4();
-    auto& param0 = o2::eventgen::GeneratorFileOrCmdParam::Instance();
-    auto& param = o2::eventgen::GeneratorHepMCParam::Instance();
-    auto& conf = o2::conf::SimConfig::Instance();
+    optnsFileName = optnsFileName.substr(0, optnsFileName.find_last_of('.')); // remove the .optns extension
     // setup the HepMC generator to run with automatic FIFOs
     gen->setup(param0, param, conf);
+    // Replace seed and optns file
+    gen->setCmd(param0.cmd + " -i " + optnsFileName);
+    gen->setSeed(randomSeed);
     return gen;
 }
diff --git a/MC/config/examples/ini/GeneratorEPOS4.ini b/MC/config/examples/ini/GeneratorEPOS4.ini
index fabfd6066..abfbb65dd 100644
--- a/MC/config/examples/ini/GeneratorEPOS4.ini
+++ b/MC/config/examples/ini/GeneratorEPOS4.ini
@@ -3,7 +3,7 @@ fileName=${O2DPG_MC_CONFIG_ROOT}/MC/config/examples/epos4/generator_EPOS4.C
 funcName=generateEPOS4("${O2DPG_MC_CONFIG_ROOT}/MC/config/examples/epos4/generator/example.optns", 2147483647)
 
 [GeneratorFileOrCmd]
-cmd=${O2DPG_MC_CONFIG_ROOT}/MC/config/examples/epos4/epos.sh -i cfg
+cmd=${O2DPG_MC_CONFIG_ROOT}/MC/config/examples/epos4/epos.sh
 bMaxSwitch=none
 
 # Set to version 2 if EPOS4.0.0 is used
diff --git a/MC/config/examples/ini/GeneratorEPOS4HQ.ini b/MC/config/examples/ini/GeneratorEPOS4HQ.ini
index de88cd801..f5804d584 100644
--- a/MC/config/examples/ini/GeneratorEPOS4HQ.ini
+++ b/MC/config/examples/ini/GeneratorEPOS4HQ.ini
@@ -4,7 +4,7 @@ fileName=${O2DPG_MC_CONFIG_ROOT}/MC/config/examples/epos4/generator_EPOS4.C
 funcName=generateEPOS4("${O2DPG_MC_CONFIG_ROOT}/MC/config/examples/epos4/generator/examplehq.optns", 2147483647)
 
 [GeneratorFileOrCmd]
-cmd=${O2DPG_MC_CONFIG_ROOT}/MC/config/examples/epos4/epos.sh -i cfg
+cmd=${O2DPG_MC_CONFIG_ROOT}/MC/config/examples/epos4/epos.sh
 bMaxSwitch=none
 
 [HepMC]