diff --git a/o_manager.py b/o_manager.py
index 5be0eaa..c290b75 100644
--- a/o_manager.py
+++ b/o_manager.py
@@ -265,14 +265,14 @@ class OManager:
         if exist_running_instance:
             # two modes on different ports
             lb_cfg_fp = self.generate_lb_cfg("fallback")
-            lb_cmd = ["go-socks-lb/go-socks-lb", "-config",
-                      lb_cfg_fp, "-bind", "0.0.0.0:7000"]
+            lb_cmd = " ".join(["go-socks-lb/go-socks-lb", "-config",
+                               lb_cfg_fp, "-bind", "0.0.0.0:7000"])
             print("lb_cmd 0", lb_cmd)
             self.lb1_pm.start(cmd=lb_cmd)
 
             lb_cfg_fp = self.generate_lb_cfg("cached-shuffle")
-            lb_cmd = ["go-socks-lb/go-socks-lb", "-config",
-                      lb_cfg_fp, "-bind", "0.0.0.0:7001"]
+            lb_cmd = " ".join(["go-socks-lb/go-socks-lb", "-config",
+                               lb_cfg_fp, "-bind", "0.0.0.0:7001"])
             print("lb_cmd 1", lb_cmd)
             self.lb2_pm.start(cmd=lb_cmd)
             #print("pre calc weights:", self.calc_weights())