diff --git a/src/common/spells/combatspells.c b/src/common/spells/combatspells.c
index cd6ac61d7..bb6ba64c7 100644
--- a/src/common/spells/combatspells.c
+++ b/src/common/spells/combatspells.c
@@ -1650,7 +1650,11 @@ sp_undeadhero(fighter * fi, int level, double power, spell * sp)
 
         /* new units gets some stats from old unit */
         free(u->display);
-        u->display = strdup(du->display);
+        if (du->display) {
+          u->display = strdup(du->display);
+        } else {
+          u->display = NULL;
+        }
         setstatus(u, du->status);
         setguard(u, GUARD_NONE);