diff --git a/doc/fixes36.2 b/doc/fixes36.2
index 8fb98475e..4a4fd0fc3 100644
--- a/doc/fixes36.2
+++ b/doc/fixes36.2
@@ -125,6 +125,8 @@ poly'd shapechanger and hiding mimic will revert to normal when cancelled,
 	like werecreature in beast form and non-Unchanging hero
 cancelled shapeshifter is no longer able to change shape
 cancelled shapeshifter hit by polymorph magic will become uncancelled
+polymorph zap which creates a new long worm (or retains an old one via wizard
+	mode monpolycontrol) can hit that worm multiple times (tail segments)
 
 
 Fixes to Post-3.6.1 Problems that Were Exposed Via git Repository
diff --git a/src/worn.c b/src/worn.c
index e7860c655..1eb1ed671 100644
--- a/src/worn.c
+++ b/src/worn.c
@@ -1,4 +1,4 @@
-/* NetHack 3.6	worn.c	$NHDT-Date: 1526728754 2018/05/19 11:19:14 $  $NHDT-Branch: NetHack-3.6.2 $:$NHDT-Revision: 1.51 $ */
+/* NetHack 3.6	worn.c	$NHDT-Date: 1537234121 2018/09/18 01:28:41 $  $NHDT-Branch: NetHack-3.6.2-beta01 $:$NHDT-Revision: 1.55 $ */
 /* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */
 /*-Copyright (c) Robert Patrick Rankin, 2013. */
 /* NetHack may be freely redistributed.  See license for details. */
@@ -710,6 +710,13 @@ clear_bypasses()
     struct obj *otmp, *nobj;
     struct monst *mtmp;
 
+    /*
+     * 'Object' bypass is also used for one monster function:
+     * polymorph control of long worms.  Activated via setting
+     * context.bypasses even if no specific object has been
+     * bypassed.
+     */
+
     for (otmp = fobj; otmp; otmp = nobj) {
         nobj = otmp->nobj;
         if (otmp->bypass) {
@@ -741,10 +748,19 @@ clear_bypasses()
             continue;
         for (otmp = mtmp->minvent; otmp; otmp = otmp->nobj)
             otmp->bypass = 0;
+        /* long worm created by polymorph has mon->mextra->mcorpsenm set
+           to PM_LONG_WORM to flag it as not being subject to further
+           polymorph (so polymorph zap won't hit monster to transform it
+           into a long worm, then hit that worm's tail and transform it
+           again on same zap); clearing mcorpsenm reverts worm to normal */
+        if (mtmp->data == &mons[PM_LONG_WORM] && has_mcorpsenm(mtmp))
+            MCORPSENM(mtmp) = NON_PM;
     }
     for (mtmp = migrating_mons; mtmp; mtmp = mtmp->nmon) {
         for (otmp = mtmp->minvent; otmp; otmp = otmp->nobj)
             otmp->bypass = 0;
+        /* no MCORPSENM(mtmp)==PM_LONG_WORM check here; long worms can't
+           be just created by polymorph and migrating at the same time */
     }
     /* billobjs and mydogs chains don't matter here */
     context.bypasses = FALSE;
diff --git a/src/zap.c b/src/zap.c
index 37b38e8ab..7a5ab3416 100644
--- a/src/zap.c
+++ b/src/zap.c
@@ -1,4 +1,4 @@
-/* NetHack 3.6	zap.c	$NHDT-Date: 1525012627 2018/04/29 14:37:07 $  $NHDT-Branch: master $:$NHDT-Revision: 1.277 $ */
+/* NetHack 3.6	zap.c	$NHDT-Date: 1537234123 2018/09/18 01:28:43 $  $NHDT-Branch: NetHack-3.6.2-beta01 $:$NHDT-Revision: 1.287 $ */
 /* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */
 /*-Copyright (c) Robert Patrick Rankin, 2013. */
 /* NetHack may be freely redistributed.  See license for details. */
@@ -222,7 +222,11 @@ struct obj *otmp;
     case WAN_POLYMORPH:
     case SPE_POLYMORPH:
     case POT_POLYMORPH:
-        if (resists_magm(mtmp)) {
+        if (mtmp->data == &mons[PM_LONG_WORM] && has_mcorpsenm(mtmp)) {
+            /* if a long worm has mcorpsenm set, it was polymophed by
+               the current zap and shouldn't be affected if hit again */
+            ;
+        } 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);
@@ -238,6 +242,7 @@ struct obj *otmp;
             if (polyspot)
                 for (obj = mtmp->minvent; obj; obj = obj->nobj)
                     bypass_obj(obj);
+
             /* natural shapechangers aren't affected by system shock
                (unless protection from shapechangers is interfering
                with their metabolism...) */
@@ -261,6 +266,22 @@ struct obj *otmp;
                                  || (u.uswallow && mtmp == u.ustuck)))
                     learn_it = TRUE;
             }
+
+            /* do this even if polymorphed failed (otherwise using
+               flags.mon_polycontrol prompting to force mtmp to remain
+               'long worm' would prompt again if zap hit another segment) */
+            if (!DEADMONSTER(mtmp) && mtmp->data == &mons[PM_LONG_WORM]) {
+                if (!has_mcorpsenm(mtmp))
+                    newmcorpsenm(mtmp);
+                /* flag to indicate that mtmp became a long worm
+                   on current zap, so further hits (on mtmp's new
+                   tail) don't do further transforms */
+                MCORPSENM(mtmp) = PM_LONG_WORM;
+                /* flag to indicate that cleanup is needed; object
+                   bypass cleanup also clears mon->mextra->mcorpsenm
+                   for all long worms on the level */
+                context.bypasses = TRUE;
+            }
         }
         break;
     case WAN_CANCELLATION: