diff --git a/doc/fixes3-7-0.txt b/doc/fixes3-7-0.txt
index 86eeb5f54..d061364e4 100644
--- a/doc/fixes3-7-0.txt
+++ b/doc/fixes3-7-0.txt
@@ -1333,6 +1333,7 @@ HP regeneration formula has changed, primarily to be less fast in the endgame
 riding negates stealth unless the steed is flying
 previous hero rising as undead in bones retains intrinsics
 level temperature affects monster generation
+amulet of unchanging cannot be polymorphed
 
 
 Fixes to 3.7.0-x General Problems Exposed Via git Repository
diff --git a/include/obj.h b/include/obj.h
index 2b40a2ee9..c747dc9d8 100644
--- a/include/obj.h
+++ b/include/obj.h
@@ -413,7 +413,8 @@ struct obj {
 
 #define unpolyable(o) ((o)->otyp == WAN_POLYMORPH \
                        || (o)->otyp == SPE_POLYMORPH \
-                       || (o)->otyp == POT_POLYMORPH)
+                       || (o)->otyp == POT_POLYMORPH \
+                       || (o)->otyp == AMULET_OF_UNCHANGING)
 
 /* achievement tracking; 3.6.x did this differently */
 #define is_mines_prize(o) ((o)->o_id == gc.context.achieveo.mines_prize_oid)