diff --git a/src/mkobj.c b/src/mkobj.c
index 2f93d43c8..a7687ca8a 100644
--- a/src/mkobj.c
+++ b/src/mkobj.c
@@ -3189,7 +3189,7 @@ mon_obj_sanity(struct monst *monlist, const char *mesg)
     for (mon = monlist; mon; mon = mon->nmon) {
         if (DEADMONSTER(mon))
             continue;
-        mwep = MON_WEP(mon);
+        mwep = MON_WEP(mon); /* mon->mw */
         if (mwep) {
             if (!mcarried(mwep))
                 insane_object(mwep, mfmt1, mesg, mon);
@@ -3209,6 +3209,18 @@ mon_obj_sanity(struct monst *monlist, const char *mesg)
             if (obj->in_use || obj->bypass || obj->nomerge
                 || (obj->otyp == BOULDER && obj->next_boulder))
                 insane_obj_bits(obj, mon);
+            if (obj == mwep)
+                mwep = (struct obj *) 0;
+        }
+        if (mwep) {
+            /* this is a monster check rather than an object check, but doing
+               it here avoids making an extra pass through mon's minvent;
+               if the full pass through that list hasn't reset mwep to Null,
+               then mwep isn't in that list where it should be */
+            impossible("monst (%s: %u) wielding %s (%u) not in %s inventory",
+                       pmname(mon->data, Mgender(mon)), mon->m_id,
+                       safe_typename(mwep->otyp), mwep->o_id, mhis(mon));
+
         }
     }
 }
diff --git a/src/mon.c b/src/mon.c
index 92a71c12a..ade679695 100644
--- a/src/mon.c
+++ b/src/mon.c
@@ -233,19 +233,6 @@ sanity_check_single_mon(
                        mtmp->m_id, distu(mtmp->mx, mtmp->my));
 #endif
     }
-    if (MON_WEP(mtmp)) { /* mtmp->mw */
-        struct obj *o;
-
-        for (o = mtmp->minvent; o; o = o->nobj)
-            if (o == MON_WEP(mtmp))
-                break;
-        if (!o) {
-            o = MON_WEP(mtmp);
-            impossible("monst (%s: %u) wielding %s (%u) not in inventory",
-                       pmname(mtmp->data, Mgender(mtmp)), mtmp->m_id,
-                       safe_typename(o->otyp), o->o_id);
-        }
-    }
 }
 
 void