diff --git a/src/gmtool.c b/src/gmtool.c
index e13701f6f..ce4c0129e 100644
--- a/src/gmtool.c
+++ b/src/gmtool.c
@@ -531,17 +531,32 @@ static void statusline(WINDOW * win, const char *str)
 }
 
 static void reset_region(region *r) {
+    unit **up = &r->units;
+    bool players = false;
+
     set_chaoscount(r, 0);
     r->flags = 0;
     a_removeall(&r->attribs, NULL);
-    while (r->units) {
-        remove_unit(&r->units, r->units);
+    while (*up) {
+        unit *u = *up;
+        if (is_monsters(u->faction)) {
+            remove_unit(up, u);
+        }
+        else {
+            players = true;
+            up = &u->next;
+        }
     }
-    while (r->ships) {
-        remove_ship(&r->ships, r->ships);
-    }
-    while (r->buildings) {
-        remove_building(&r->buildings, r->buildings);
+    if (!players) {
+        while (r->ships) {
+            remove_ship(&r->ships, r->ships);
+        }
+        while (r->buildings) {
+            remove_building(&r->buildings, r->buildings);
+        }
+        if (r->land) {
+            init_region(r);
+        }
     }
 }
 
diff --git a/src/kernel/region.c b/src/kernel/region.c
index 68b47d7a2..7cb52c201 100644
--- a/src/kernel/region.c
+++ b/src/kernel/region.c
@@ -1048,6 +1048,43 @@ int fix_demand(region * rd) {
     return -1;
 }
 
+void init_region(region *r)
+{
+    static int changed;
+    static const terrain_type *t_plain;
+    const terrain_type * terrain = r->terrain;
+    int horses = 0, trees = 0;
+    if (terrain_changed(&changed)) {
+        t_plain = get_terrain(terrainnames[T_PLAIN]);
+    }
+    if (terrain->size>0) {
+        horses = rng_int() % (terrain->size / 50);
+        trees = terrain->size * (30 + rng_int() % 40) / 1000;
+    }
+    if (t_plain && terrain == t_plain) {
+        rsethorses(r, horses);
+        if (chance(0.4)) {
+            rsettrees(r, 2, trees);
+        }
+    }
+    else if (trees>0 && chance(0.2)) {
+        rsettrees(r, 2, trees);
+    }
+    else {
+        rsettrees(r, 2, 0);
+    }
+    rsettrees(r, 1, rtrees(r, 2) / 4);
+    rsettrees(r, 0, rtrees(r, 2) / 8);
+
+    if (!fval(r, RF_CHAOTIC)) {
+        int peasants;
+        peasants = (region_maxworkers(r) * (20 + dice(6, 10))) / 100;
+        rsetpeasants(r, MAX(100, peasants));
+        rsetmoney(r, rpeasants(r) * ((wage(r, NULL, NULL,
+            INT_MAX) + 1) + rng_int() % 5));
+    }
+}
+
 void terraform_region(region * r, const terrain_type * terrain)
 {
     /* Resourcen, die nicht mehr vorkommen können, löschen */
@@ -1195,40 +1232,8 @@ void terraform_region(region * r, const terrain_type * terrain)
             else
                 freset(r, RF_MALLORN);
         }
-    }
-
-    if (oldterrain == NULL || terrain->size != oldterrain->size) {
-        static int changed;
-        static const terrain_type *t_plain;
-        int horses = 0, trees = 0;
-        if (terrain_changed(&changed)) {
-            t_plain = get_terrain(terrainnames[T_PLAIN]);
-        }
-        if (terrain->size>0) {
-            horses = rng_int() % (terrain->size / 50);
-            trees = terrain->size * (30 + rng_int() % 40) / 1000;
-        }
-        if (t_plain && terrain == t_plain) {
-            rsethorses(r, horses);
-            if (chance(0.4)) {
-                rsettrees(r, 2, trees);
-            }
-        }
-        else if (trees>0 && chance(0.2)) {
-            rsettrees(r, 2, trees);
-        }
-        else {
-            rsettrees(r, 2, 0);
-        }
-        rsettrees(r, 1, rtrees(r, 2) / 4);
-        rsettrees(r, 0, rtrees(r, 2) / 8);
-
-        if (!fval(r, RF_CHAOTIC)) {
-            int peasants;
-            peasants = (region_maxworkers(r) * (20 + dice(6, 10))) / 100;
-            rsetpeasants(r, MAX(100, peasants));
-            rsetmoney(r, rpeasants(r) * ((wage(r, NULL, NULL,
-                INT_MAX) + 1) + rng_int() % 5));
+        if (oldterrain == NULL || terrain->size != oldterrain->size) {
+            init_region(r);
         }
     }
 }
diff --git a/src/kernel/region.h b/src/kernel/region.h
index 9543658d9..bf932e9c3 100644
--- a/src/kernel/region.h
+++ b/src/kernel/region.h
@@ -228,6 +228,7 @@ extern "C" {
     struct region *new_region(int x, int y, struct plane *pl, int uid);
     void remove_region(region ** rlist, region * r);
     void terraform_region(struct region *r, const struct terrain_type *terrain);
+    void init_region(struct region *r);
     bool pnormalize(int *x, int *y, const struct plane *pl);
 
     extern const int delta_x[MAXDIRECTIONS];