diff --git a/include/extern.h b/include/extern.h
index 879fcc7dd..84d61a8e1 100644
--- a/include/extern.h
+++ b/include/extern.h
@@ -1782,6 +1782,7 @@ extern void mimic_hit_msg(struct monst *, short);
 extern void adj_erinys(unsigned);
 extern void see_monster_closeup(struct monst *) NONNULLARG1;
 extern void see_nearby_monsters(void);
+extern void shieldeff_mon(struct monst *) NONNULLARG1;
 
 /* ### mondata.c ### */
 
diff --git a/src/mhitm.c b/src/mhitm.c
index c92cb7d40..a65ed98d7 100644
--- a/src/mhitm.c
+++ b/src/mhitm.c
@@ -1137,7 +1137,7 @@ mon_poly(struct monst *magr, struct monst *mdef, int dmg)
         if (resists_magm(mdef)) {
             /* Magic resistance */
             if (gv.vis)
-                shieldeff(mdef->mx, mdef->my);
+                shieldeff_mon(mdef);
         } else if (resist(mdef, WAND_CLASS, 0, TELL)) {
             /* general resistance to magic... */
             ;
diff --git a/src/mon.c b/src/mon.c
index 4767920d7..cf77dd8c6 100644
--- a/src/mon.c
+++ b/src/mon.c
@@ -5838,4 +5838,15 @@ see_nearby_monsters(void)
             }
 }
 
+/* monster resists something.
+   make a shield effect at monster's location and give a message */
+void
+shieldeff_mon(struct monst *mtmp)
+{
+    shieldeff(mtmp->mx, mtmp->my);
+    /* does not depend on seeing the monster; the shield effect is visible */
+    if (cansee(mtmp->mx, mtmp->my))
+        pline_xy(mtmp->mx, mtmp->my, "%s resists!", Monnam(mtmp));
+}
+
 /*mon.c*/
diff --git a/src/trap.c b/src/trap.c
index 64e185d32..d1be7d9b5 100644
--- a/src/trap.c
+++ b/src/trap.c
@@ -2444,7 +2444,7 @@ trapeffect_poly_trap(
         boolean in_sight = canseemon(mtmp) || (mtmp == u.usteed);
 
         if (resists_magm(mtmp)) {
-            shieldeff(mtmp->mx, mtmp->my);
+            shieldeff_mon(mtmp);
         } else if (!resist(mtmp, WAND_CLASS, 0, NOTELL)) {
             (void) newcham(mtmp, (struct permonst *) 0, NC_SHOW_MSG);
             if (in_sight)
diff --git a/src/zap.c b/src/zap.c
index 00120647a..23fdac1be 100644
--- a/src/zap.c
+++ b/src/zap.c
@@ -265,7 +265,7 @@ bhitm(struct monst *mtmp, struct obj *otmp)
         } else if (resists_magm(mtmp)) {
             /* magic resistance protects from polymorph traps, so make
                it guard against involuntary polymorph attacks too... */
-            shieldeff(mtmp->mx, mtmp->my);
+            shieldeff_mon(mtmp);
         } else if (!resist(mtmp, otmp->oclass, 0, NOTELL)) {
             boolean polyspot = (otyp != POT_POLYMORPH),
                     give_msg = (!Hallucination
@@ -510,7 +510,7 @@ bhitm(struct monst *mtmp, struct obj *otmp)
         if (otyp == SPE_DRAIN_LIFE)
             dmg = spell_damage_bonus(dmg);
         if (resists_drli(mtmp)) {
-            shieldeff(mtmp->mx, mtmp->my);
+            shieldeff_mon(mtmp);
         } else if (!resist(mtmp, otmp->oclass, dmg, NOTELL)
                    && !DEADMONSTER(mtmp)) {
             mtmp->mhp -= dmg;
@@ -6068,10 +6068,8 @@ resist(struct monst *mtmp, char oclass, int damage, int tell)
 
     resisted = rn2(100 + alev - dlev) < mtmp->data->mr;
     if (resisted) {
-        if (tell) {
-            shieldeff(mtmp->mx, mtmp->my);
-            pline("%s resists!", Monnam(mtmp));
-        }
+        if (tell)
+            shieldeff_mon(mtmp);
         damage = (damage + 1) / 2;
     }