diff --git a/dat/data.base b/dat/data.base
index 4a964c905..f098dd7c7 100644
--- a/dat/data.base
+++ b/dat/data.base
@@ -5374,11 +5374,10 @@ vlad*
 *vortex
 vortices
 	Swirling clouds of pure elemental energies, the vortices are
-	thought to be related to the larger elementals.  Though the
-	vortices do no damage when touched, they are noted for being
-	able to envelop unwary travellers.  The hapless fool thus
-	swallowed by a vortex will soon perish from exposure to the
-	element the vortex is composed of.
+	thought to be related to the larger elementals.  They are 
+	noted for being able to envelop unwary travellers.  The 
+	hapless fool thus swallowed by a vortex will soon perish from
+	exposure to the element the vortex is composed of.
 vrock
 	The vrock is one of the weaker forms of demon.  It resembles
 	a cross between a human being and a vulture and does physical
diff --git a/doc/fixes36.3 b/doc/fixes36.3
index 5ff4a1850..28564e3da 100644
--- a/doc/fixes36.3
+++ b/doc/fixes36.3
@@ -18,6 +18,9 @@ glob pricing did not consider weight properly
 glob shop interaction improved to handle more of the expected scenarios
 non-flying steed on Plane of Water would drown when air bubble moved hero
 xans fly, but could not reach your feet if you flew
+adjust vortex database entry to be consistent with fire and energy vortices
+when co-located with a boulder you could sometimes swap places with pets of
+	any size
 
 
 Fixes to Post-3.6.2 Problems that Were Exposed Via git Repository
diff --git a/src/hack.c b/src/hack.c
index 18709fcb4..5f0da7986 100644
--- a/src/hack.c
+++ b/src/hack.c
@@ -1352,7 +1352,8 @@ domove_core()
     xchar chainx = 0, chainy = 0,
           ballx = 0, bally = 0;         /* ball&chain new positions */
     int bc_control = 0;                 /* control for ball&chain */
-    boolean cause_delay = FALSE;        /* dragging ball will skip a move */
+    boolean cause_delay = FALSE,        /* dragging ball will skip a move */
+            u_with_boulder = (sobj_at(BOULDER, u.ux, u.uy) != 0);
 
     if (g.context.travel) {
         if (!findtravelpath(FALSE))
@@ -1779,7 +1780,16 @@ domove_core()
             if (u.usteed)
                 u.usteed->mx = u.ux, u.usteed->my = u.uy;
             You("stop.  %s can't move diagonally.", upstart(y_monnam(mtmp)));
-        } else if (u.ux0 != x && u.uy0 != y && bad_rock(mtmp->data, x, u.uy0)
+         } else if (u_with_boulder
+                    && !(verysmall(mtmp->data)
+                         && (!mtmp->minvent || (curr_mon_load(mtmp) <= 600)))) {
+            /* can't swap places when pet won't fit there with the boulder */
+            u.ux = u.ux0, u.uy = u.uy0; /* didn't move after all */
+            if (u.usteed)
+                u.usteed->mx = u.ux, u.usteed->my = u.uy;
+            You("stop.  %s won't fit into the same spot that you're at.",
+                 upstart(y_monnam(mtmp)));
+         } else if (u.ux0 != x && u.uy0 != y && bad_rock(mtmp->data, x, u.uy0)
                    && bad_rock(mtmp->data, u.ux0, y)
                    && (bigmonst(mtmp->data) || (curr_mon_load(mtmp) > 600))) {
             /* can't swap places when pet won't fit thru the opening */