diff --git a/doc/fixes36.2 b/doc/fixes36.2
index 3454dda9e..8fb98475e 100644
--- a/doc/fixes36.2
+++ b/doc/fixes36.2
@@ -120,6 +120,11 @@ handle monsters inside the invocation area
 give monsters who have had a worn item stolen or who have been life-saved
 	(used up amulet) a chance to wear replacement gear on next move
 	instead of having to wait until they pick something up
+Unchanging hero in clay golem form will be killed when cancelled
+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
 
 
 Fixes to Post-3.6.1 Problems that Were Exposed Via git Repository
diff --git a/src/mon.c b/src/mon.c
index cbdde81ba..9cdf9b6d9 100644
--- a/src/mon.c
+++ b/src/mon.c
@@ -2900,7 +2900,8 @@ restartcham()
     for (mtmp = fmon; mtmp; mtmp = mtmp->nmon) {
         if (DEADMONSTER(mtmp))
             continue;
-        mtmp->cham = pm_to_cham(monsndx(mtmp->data));
+        if (!mtmp->mcan)
+            mtmp->cham = pm_to_cham(monsndx(mtmp->data));
         if (mtmp->data->mlet == S_MIMIC && mtmp->msleeping
             && cansee(mtmp->mx, mtmp->my)) {
             set_mimic_sym(mtmp);
@@ -3417,6 +3418,13 @@ boolean msg;      /* "The oldmon turns into a newmon!" */
            anomalous extinction feedback during final disclsoure */
         if (mbirth_limit(monsndx(olddata)) < MAXMONNO)
             return 0;
+        /* cancelled shapechangers become uncancelled prior
+           to being given a new shape */
+        if (mtmp->mcan && !Protection_from_shape_changers) {
+            mtmp->cham = pm_to_cham(monsndx(mtmp->data));
+            if (mtmp->cham != NON_PM)
+                mtmp->mcan = 0;
+        }
     }
 
     if (msg) {
diff --git a/src/zap.c b/src/zap.c
index 14b47902a..37b38e8ab 100644
--- a/src/zap.c
+++ b/src/zap.c
@@ -2306,7 +2306,7 @@ boolean ordinary;
 
     case WAN_CANCELLATION:
     case SPE_CANCELLATION:
-        (void) cancel_monst(&youmonst, obj, TRUE, FALSE, TRUE);
+        (void) cancel_monst(&youmonst, obj, TRUE, TRUE, TRUE);
         break;
 
     case SPE_DRAIN_LIFE:
@@ -2675,25 +2675,45 @@ boolean youattack, allow_cancel_kill, self_cancel;
 
     /* now handle special cases */
     if (youdefend) {
-        if (Upolyd) {
-            if ((u.umonnum == PM_CLAY_GOLEM) && !Blind)
-                pline(writing_vanishes, your);
-
-            if (Unchanging)
+        if (Upolyd) { /* includes lycanthrope in creature form */
+            /*
+             * Return to normal form unless Unchanging.
+             * Hero in clay golem form dies if Unchanging.
+             * Does not cure lycanthropy or stop timed random polymorph.
+             */
+            if (u.umonnum == PM_CLAY_GOLEM) {
+                if (!Blind)
+                    pline(writing_vanishes, your);
+                else /* note: "dark" rather than "heavy" is intentional... */
+                    You_feel("%s headed.", Hallucination ? "dark" : "light");
+                u.mh = 0; /* fatal; death handled by rehumanize() */
+            }
+            if (Unchanging && u.mh > 0)
                 Your("amulet grows hot for a moment, then cools.");
             else
                 rehumanize();
         }
     } else {
-        mdef->mcan = TRUE;
-
-        if (is_were(mdef->data) && mdef->data->mlet != S_HUMAN)
+        mdef->mcan = 1;
+        /* force shapeshifter into its base form */
+        if (mdef->m_ap_type != M_AP_NOTHING)
+            seemimic(mdef);
+        /* [not 'else if'; chameleon might have been hiding as a mimic] */
+        if (mdef->cham >= LOW_PM) {
+            /* note: newcham() uncancels shapechangers (resets m->mcan
+               to 0), but only for shapechangers whose m->cham is already
+               NON_PM and we just verified that it's LOW_PM or higher */
+            newcham(mdef, &mons[mdef->cham], FALSE, FALSE);
+            mdef->cham = NON_PM; /* cancelled shapeshifter can't shift */
+        }
+        if (is_were(mdef->data) && !is_human(mdef->data))
             were_change(mdef);
 
         if (mdef->data == &mons[PM_CLAY_GOLEM]) {
             if (canseemon(mdef))
                 pline(writing_vanishes, s_suffix(mon_nam(mdef)));
-
+            /* !allow_cancel_kill is for Magicbane, where clay golem
+               will be killed somewhere back up the call/return chain... */
             if (allow_cancel_kill) {
                 if (youattack)
                     killed(mdef);