diff --git a/sw/ground_segment/tmtc/link.ml b/sw/ground_segment/tmtc/link.ml
index 2585e7736e..67fff0891e 100644
--- a/sw/ground_segment/tmtc/link.ml
+++ b/sw/ground_segment/tmtc/link.ml
@@ -74,7 +74,7 @@ let ping_msg_period = ref 5000 (** ms  *)
 
 (* Time (in ms) after which an aircraft is regarded as dead/off if no messages are received.
    If an aircraft is not live anymore, no uplink messages are sent.
-   Set to a negative number to disable this feature.
+   Set to a zero (or negative number) to disable this feature.
 *)
 let dead_aircraft_time_ms = ref 5000
 
@@ -141,7 +141,7 @@ let status_ping_diff = 500 (* ms *)
 let live_aircraft = fun ac_id ->
   try
     let s = Hashtbl.find statuss ac_id in
-    s.ms_since_last_msg < !dead_aircraft_time_ms
+    !dead_aircraft_time_ms <= 0 || s.ms_since_last_msg < !dead_aircraft_time_ms
   with
       Not_found -> false
 
@@ -492,7 +492,7 @@ let () =
       "-id", Arg.Set_int link_id, (sprintf "<id> Sets the link id. If multiple links are used, each must have a unique id. Default is %i" !link_id);
       "-status_period", Arg.Set_int status_msg_period, (sprintf "<period> Sets the period (in ms) of the LINK_REPORT status message. Default is %i" !status_msg_period);
       "-ping_period", Arg.Set_int ping_msg_period, (sprintf "<period> Sets the period (in ms) of the PING message sent to aircrafs. Default is %i" !ping_msg_period);
-      "-ac_timeout", Arg.Set_int dead_aircraft_time_ms, (sprintf "<time> Sets the time (in ms) after which an aircraft is regarded as dead/off if no messages are received. Default is %i, set to negative to disable." !ping_msg_period)
+      "-ac_timeout", Arg.Set_int dead_aircraft_time_ms, (sprintf "<time> Sets the time (in ms) after which an aircraft is regarded as dead/off if no messages are received. Default is %ims, set to zero to disable." !ping_msg_period)
     ] in
   Arg.parse options (fun _x -> ()) "Usage: ";