diff --git a/pilot/eventservice/esprocess/esprocess.py b/pilot/eventservice/esprocess/esprocess.py
index 6d727497..6cff30ce 100644
--- a/pilot/eventservice/esprocess/esprocess.py
+++ b/pilot/eventservice/esprocess/esprocess.py
@@ -162,7 +162,7 @@ def init_yampl_socket(self, executable: str) -> str:
         is_mt = "--multithreaded=true" in executable.lower()
         if is_ca:
             if is_mt:
-                preexec_socket_config = f" --mtes=True --mtes_channel=\"{socket_name}\" "
+                preexec_socket_config = f" --mtes=True --mtes-channel=\"{socket_name}\" "
             else:
                 preexec_socket_config = f" --preExec 'ConfigFlags.MP.EventRangeChannel=\"{socket_name}\"' "
         else: