diff --git a/src/kernel/region.c b/src/kernel/region.c
index 5cb86ff47..b582c406e 100644
--- a/src/kernel/region.c
+++ b/src/kernel/region.c
@@ -917,6 +917,7 @@ void free_region(region * r)
     while (r->units) {
         unit *u = r->units;
         r->units = u->next;
+        u->region = NULL;
         uunhash(u);
         free_unit(u);
         free(u);
diff --git a/src/kernel/save.c b/src/kernel/save.c
index 7a9e12286..83a218622 100644
--- a/src/kernel/save.c
+++ b/src/kernel/save.c
@@ -1707,6 +1707,7 @@ int read_game(gamedata *data) {
 
             if (data->version < NORCSPELL_VERSION && u_race(u) == rc_spell) {
                 set_observer(r, u->faction, get_level(u, SK_PERCEPTION), u->age);
+                u_setfaction(u, NULL);
                 free_unit(u);
             }
             else {
diff --git a/src/kernel/unit.c b/src/kernel/unit.c
index e6b8757ef..7b6f135fc 100644
--- a/src/kernel/unit.c
+++ b/src/kernel/unit.c
@@ -1404,6 +1404,7 @@ int invisible(const unit * target, const unit * viewer)
  */
 void free_unit(unit * u)
 {
+    assert(!u->region);
     free(u->_name);
     free(u->display);
     free_order(u->thisorder);
diff --git a/src/magic.c b/src/magic.c
index 3cac1cb52..93c5009f5 100644
--- a/src/magic.c
+++ b/src/magic.c
@@ -3010,7 +3010,6 @@ int cast_spell(struct castorder *co)
 
     fun = get_spellcast(sp->sname);
     if (!fun) {
-        log_warning("no spell function for %s, try callback", sp->sname);
         return callbacks.cast_spell(co, fname);
     }
     return fun(co);