diff --git a/src/common/races/zombies.c b/src/common/races/zombies.c
index 8d71aae99..eb5c636c9 100644
--- a/src/common/races/zombies.c
+++ b/src/common/races/zombies.c
@@ -84,7 +84,7 @@ void
 age_skeleton(unit *u)
 {
 	if (u->faction->no == 0 && rand()%100 < age_chance(u->age, 27, 1)) {
-		int n = (u->number+1)/2;
+		int n = max(1,u->number/2);
 		double q = (double) u->hp / (double) (unit_max_hp(u) * u->number);
 		u->race = new_race[RC_SKELETON_LORD];
 		u->irace = new_race[RC_SKELETON_LORD];
@@ -97,7 +97,7 @@ void
 age_zombie(unit *u)
 {
 	if (u->faction->no == 0 && rand()%100 < age_chance(u->age, 27, 1)) {
-		int n = (u->number+1)/2;
+		int n = max(1,u->number/2);
 		double q = (double) u->hp / (double) (unit_max_hp(u) * u->number);
 		u->race = new_race[RC_ZOMBIE_LORD];
 		u->irace = new_race[RC_ZOMBIE_LORD];
@@ -110,7 +110,7 @@ void
 age_ghoul(unit *u)
 {
 	if (u->faction->no == 0 && rand()%100 < age_chance(u->age, 27, 1)) {
-		int n = (u->number+1)/2;
+		int n = max(1,u->number/2);
 		double q = (double) u->hp / (double) (unit_max_hp(u) * u->number);
 		u->race = new_race[RC_GHOUL_LORD];
 		u->irace = new_race[RC_GHOUL_LORD];