diff --git a/MC/bin/o2dpg_sim_config.py b/MC/bin/o2dpg_sim_config.py
index 028dd0bfd..1f5696e75 100755
--- a/MC/bin/o2dpg_sim_config.py
+++ b/MC/bin/o2dpg_sim_config.py
@@ -134,6 +134,7 @@ def add(cfg, flatconfig):
     # ----- add default settings -----
 
     add(config, {"MFTBase.buildAlignment" : "true"})
+    add(config, {"GenTPCLoopers.colsys" : args.col})
 
     # ----- apply external overwrites from command line -------
     for keyval in externalConfigString.split(";"):