diff --git a/doc/fixes3-7-0.txt b/doc/fixes3-7-0.txt
index 171e1daa4..59c957b26 100644
--- a/doc/fixes3-7-0.txt
+++ b/doc/fixes3-7-0.txt
@@ -1684,6 +1684,8 @@ paranoid_confirm:Autoall for menustyle:full has the test handling backward and
 applying a wielded lump of royal jelly but not picking something to rub it on
 	while other lumps of jelly were quivered would trigger a panic,
 	"addinv: null obj after quiver merge" (like applying lit potion of oil)
+ceiling hider could become hidden when there was no ceiling, triggering a
+	warning if sanity_check was On
 
 
 Fixes to 3.7.0-x Platform and/or Interface Problems Exposed Via git Repository
diff --git a/src/mon.c b/src/mon.c
index 980060cf1..093076d71 100644
--- a/src/mon.c
+++ b/src/mon.c
@@ -4214,6 +4214,9 @@ restrap(struct monst *mtmp)
         /* can't hide while trapped except in pits */
         || (mtmp->mtrapped && (t = t_at(mtmp->mx, mtmp->my)) != 0
             && !is_pit(t->ttyp))
+        /* can't hide on ceiling if there isn't one */
+        || (ceiling_hider(mtmp->data) && !has_ceiling(&u.uz))
+        /* won't hide when adjacent to hero */
         || (sensemon(mtmp) && next2u(mtmp->mx, mtmp->my)))
         return FALSE;