diff --git a/src/lib/subs/aircombat.c b/src/lib/subs/aircombat.c
index 93f5f3f6..4ae807c6 100644
--- a/src/lib/subs/aircombat.c
+++ b/src/lib/subs/aircombat.c
@@ -778,6 +778,10 @@ getilists(struct emp_qelem *list, unsigned char *rel, natid intruder)
 	    continue;
 	if (plane.pln_effic < 40)
 	    continue;
+	if (opt_MARKET) {
+	    if (ontradingblock(EF_PLANE, &plane))
+		continue;
+	}
 	if (!pln_airbase_ok(&plane, 0, 0))
 	    continue;
 	/* got one! */
diff --git a/src/lib/subs/mslsub.c b/src/lib/subs/mslsub.c
index db7afb5a..2a3dff0f 100644
--- a/src/lib/subs/mslsub.c
+++ b/src/lib/subs/mslsub.c
@@ -207,6 +207,10 @@ msl_sel(struct emp_qelem *list, coord x, coord y, natid victim,
 	    continue;
 	if (plane.pln_effic < 100)
 	    continue;
+	if (opt_MARKET) {
+	    if (ontradingblock(EF_PLANE, &plane))
+		continue;
+	}
 	if (!pln_airbase_ok(&plane, 1, 0))
 	    continue;
 	/* got a valid interceptor */