diff --git a/info/Bugs.t b/info/Bugs.t
index 4061a1ed..9e9cf107 100644
--- a/info/Bugs.t
+++ b/info/Bugs.t
@@ -16,9 +16,6 @@ If a ship, plane, land unit or nuke is out to trade, and gets
 destroyed, and its owner builds a new one that gets the same number,
 it will go on the trading market automatically.
 .s1
-If a plane has negative mobility, then gets traded, mobility
-goes to 0.
-.s1
 If two countries are cooperating,
 its possible to raid an enemy airport and steal the planes
 by putting them out to trade.
diff --git a/src/lib/commands/trad.c b/src/lib/commands/trad.c
index 2e24a29b..a760886a 100644
--- a/src/lib/commands/trad.c
+++ b/src/lib/commands/trad.c
@@ -358,7 +358,7 @@ check_trade(void)
 	    if (opt_MOB_ACCESS) {
 		tg.plane.pln_mobil = -(etu_per_update / sect_mob_neg_factor);
 		game_tick_to_now(&tg.plane.pln_access);
-	    } else {
+	    } else if (tg.plane.pln_mobil > 0) {
 		tg.plane.pln_mobil = 0;
 	    }
 	    tg.plane.pln_harden = 0;
@@ -373,7 +373,7 @@ check_trade(void)
 	    if (opt_MOB_ACCESS) {
 		tg.land.lnd_mobil = -(etu_per_update / sect_mob_neg_factor);
 		game_tick_to_now(&tg.land.lnd_access);
-	    } else {
+	    } else if (tg.plane.pln_mobil > 0) {
 		tg.land.lnd_mobil = 0;
 	    }
 	    tg.land.lnd_harden = 0;