diff --git a/MC/bin/o2dpg_sim_workflow_anchored.py b/MC/bin/o2dpg_sim_workflow_anchored.py
index 13c6959bb..2fa3f73cf 100755
--- a/MC/bin/o2dpg_sim_workflow_anchored.py
+++ b/MC/bin/o2dpg_sim_workflow_anchored.py
@@ -536,7 +536,9 @@ def main():
     # TODO: this needs to be done in a pythonic way clearly
     # NOTE: forwardargs can - in principle - contain some of the arguments that are appended here. However, the last passed argument wins, so they would be overwritten.
     forwardargs += " -tf " + str(args.tf) + " --sor " + str(run_start) + " --timestamp " + str(timestamp) + " --production-offset " + str(prod_offset) + " -run " + str(args.run_number) + " --run-anchored --first-orbit "       \
-                   + str(GLOparams["FirstOrbit"]) + " -field ccdb -bcPatternFile ccdb" + " --orbitsPerTF " + str(GLOparams["OrbitsPerTF"]) + " -col " + str(ColSystem) + " -eCM " + str(eCM) + ' --readoutDets ' + GLOparams['detList']
+                   + str(GLOparams["FirstOrbit"]) + " -field ccdb -bcPatternFile ccdb" + " --orbitsPerTF " + str(GLOparams["OrbitsPerTF"]) + " -col " + str(ColSystem) + " -eCM " + str(eCM)
+    if not '--readoutDets' in forwardargs:
+       forwardargs += ' --readoutDets ' + GLOparams['detList']
     print ("forward args ", forwardargs)
     cmd = "${O2DPG_ROOT}/MC/bin/o2dpg_sim_workflow.py " + forwardargs