diff --git a/src/hack.c b/src/hack.c
index 497ee3582..636ee7ab3 100644
--- a/src/hack.c
+++ b/src/hack.c
@@ -243,7 +243,7 @@ moverock(void)
                 || doorless_door(rx, ry)) && !sobj_at(BOULDER, rx, ry)) {
             ttmp = t_at(rx, ry);
             mtmp = m_at(rx, ry);
-            costly = (!otmp->no_charge && costly_spot(sx, sy)
+            costly = (costly_spot(sx, sy)
                       && shop_keeper(*in_rooms(sx, sy, SHOPBASE)));
 
             /* KMH -- Sokoban doesn't let you push boulders diagonally */
@@ -383,7 +383,7 @@ moverock(void)
                         (void) rloco(otmp);
                     } else {
                         if (costly)
-                            addtobill(otmp, FALSE, FALSE, FALSE);
+                            stolen_value(otmp, rx, ry, !ttmp->tseen, FALSE);
                         obj_extract_self(otmp);
                         add_to_migration(otmp);
                         get_level(&dest, newlev);
@@ -451,6 +451,12 @@ moverock(void)
                            != 0)
                        && onshopbill(otmp, shkp, TRUE)) {
                 subfrombill(otmp, shkp);
+            } else if (otmp->unpaid && !*in_rooms(rx, ry, SHOPBASE)
+                       && *in_rooms(sx, sy, SHOPBASE)) {
+                /* once the boulder is fully out of the shop, so that it's
+                 * impossible to change your mind and push it back in without
+                 * leaving and triggering Kops, switch it to stolen_value */
+                stolen_value(otmp, sx, sy, TRUE, FALSE);
             }
         } else {
  nopushmsg:
diff --git a/src/mkobj.c b/src/mkobj.c
index 8461369ef..38b967525 100644
--- a/src/mkobj.c
+++ b/src/mkobj.c
@@ -2463,6 +2463,11 @@ add_to_migration(struct obj *obj)
     if (obj->where != OBJ_FREE)
         panic("add_to_migration: obj not free");
 
+    if (obj->unpaid) /* caller should have changed unpaid item to stolen */
+        impossible("unpaid object migrating to another level? [%s]",
+                   simpleonames(obj));
+    obj->no_charge = 0; /* was only relevant while inside a shop */
+
     /* lock picking context becomes stale if it's for this object */
     if (Is_container(obj))
         maybe_reset_pick(obj);
@@ -2830,7 +2835,7 @@ shop_obj_sanity(struct obj *obj, const char *mesg)
            and for objects inside floor containers in shops */
         if (otop->where != OBJ_FLOOR)
             why = "%s no_charge obj not on floor! %s %s: %s";
-        else if (!costly)
+        else if (!costly && !costlytoo)
             why = "%s no_charge obj not inside tended shop! %s %s: %s";
         else if (!shkp)
             why = "%s no_charge obj inside untended shop! %s %s: %s";