diff --git a/doc/fixes37.0 b/doc/fixes37.0
index e24f9302c..72352f307 100644
--- a/doc/fixes37.0
+++ b/doc/fixes37.0
@@ -1,4 +1,4 @@
-$NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.256 $ $NHDT-Date: 1595668889 2020/07/25 09:21:29 $
+$NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.257 $ $NHDT-Date: 1595774758 2020/07/26 14:45:58 $
 
 General Fixes and Modified Features
 -----------------------------------
@@ -228,6 +228,7 @@ hero poly'd into a mind flayer who used #monster to emit a psychic blast was
 some hero attacks that should have gotten a skill bonus or penalty didn't
 change internal name of "<foo> venom" to "splash of <foo> venom"
 singularize "splashes" to "splash" instead of "splashe"
+treat slinging gems and tossing or slinging stones at unicorns as attacks
 
 
 Fixes to 3.7.0-x Problems that Were Exposed Via git Repository
diff --git a/src/dothrow.c b/src/dothrow.c
index 1e6930c8e..f5d93cd37 100644
--- a/src/dothrow.c
+++ b/src/dothrow.c
@@ -1,4 +1,4 @@
-/* NetHack 3.6	dothrow.c	$NHDT-Date: 1584398443 2020/03/16 22:40:43 $  $NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.184 $ */
+/* NetHack 3.6	dothrow.c	$NHDT-Date: 1595774758 2020/07/26 14:45:58 $  $NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.187 $ */
 /* Copyright (c) Stichting Mathematisch Centrum, Amsterdam, 1985. */
 /*-Copyright (c) Robert Patrick Rankin, 2013. */
 /* NetHack may be freely redistributed.  See license for details. */
@@ -1611,7 +1611,13 @@ register struct obj *obj; /* g.thrownobj or g.kickedobj or uwep */
         tmp += 1000; /* Guaranteed hit */
     }
 
-    if (obj->oclass == GEM_CLASS && is_unicorn(mon->data)) {
+    /* throwing real gems to co-aligned unicorns boosts Luck,
+       to cross-aligned unicorns changes Luck by random amount;
+       throwing worthless glass doesn't affect Luck but doesn't anger them;
+       3.7: treat rocks and gray stones as attacks rather than like glass
+       and also treat gems or glass shot via sling as attacks */
+    if (obj->oclass == GEM_CLASS && is_unicorn(mon->data)
+        && objects[obj->otyp].oc_material != MINERAL && !uslinging()) {
         if (mon->msleeping || !mon->mcanmove) {
             tmiss(obj, mon, FALSE);
             return 0;
@@ -1628,8 +1634,8 @@ register struct obj *obj; /* g.thrownobj or g.kickedobj or uwep */
        at leader... (kicked artifact is ok too; HMON_APPLIED could
        occur if quest artifact polearm or grapnel ever gets added) */
     if (hmode != HMON_APPLIED && quest_arti_hits_leader(obj, mon)) {
-        /* AIS: changes to wakeup() means that it's now less inappropriate here
-           than it used to be, but the manual version works just as well */
+        /* AIS: changes to wakeup() means that it's now less inappropriate
+           here than it used to be, but manual version works just as well */
         mon->msleeping = 0;
         mon->mstrategy &= ~STRAT_WAITMASK;
 
@@ -1823,15 +1829,16 @@ gem_accept(mon, obj)
 register struct monst *mon;
 register struct obj *obj;
 {
+    static NEARDATA const char
+        nogood[]     = " is not interested in your junk.",
+        acceptgift[] = " accepts your gift.",
+        maybeluck[]  = " hesitatingly",
+        noluck[]     = " graciously",
+        addluck[]    = " gratefully";
     char buf[BUFSZ];
     boolean is_buddy = sgn(mon->data->maligntyp) == sgn(u.ualign.type);
     boolean is_gem = objects[obj->otyp].oc_material == GEMSTONE;
     int ret = 0;
-    static NEARDATA const char nogood[] = " is not interested in your junk.";
-    static NEARDATA const char acceptgift[] = " accepts your gift.";
-    static NEARDATA const char maybeluck[] = " hesitatingly";
-    static NEARDATA const char noluck[] = " graciously";
-    static NEARDATA const char addluck[] = " gratefully";
 
     Strcpy(buf, Monnam(mon));
     mon->mpeaceful = 1;
@@ -1851,7 +1858,8 @@ register struct obj *obj;
             Strcat(buf, nogood);
             goto nopick;
         }
-        /* making guesses */
+
+    /* making guesses */
     } else if (has_oname(obj) || objects[obj->otyp].oc_uname) {
         if (is_gem) {
             if (is_buddy) {
@@ -1865,7 +1873,8 @@ register struct obj *obj;
             Strcat(buf, nogood);
             goto nopick;
         }
-        /* value completely unknown to @ */
+
+    /* value completely unknown to @ */
     } else {
         if (is_gem) {
             if (is_buddy) {