diff --git a/src/explode.c b/src/explode.c
index 768aa72c9..c2b76bf4a 100644
--- a/src/explode.c
+++ b/src/explode.c
@@ -840,7 +840,10 @@ scatter(coordxy sx, coordxy sy,  /* location of objects to scatter */
                 gt.thrownobj = stmp->obj; /* mainly in case it kills hero */
                 gb.bhitpos.x = stmp->ox + stmp->dx;
                 gb.bhitpos.y = stmp->oy + stmp->dy;
-                typ = levl[gb.bhitpos.x][gb.bhitpos.y].typ;
+                if (isok(gb.bhitpos.x, gb.bhitpos.y))
+                    typ = levl[gb.bhitpos.x][gb.bhitpos.y].typ;
+                else
+                    typ = STONE;
                 if (!isok(gb.bhitpos.x, gb.bhitpos.y)) {
                     gb.bhitpos.x -= stmp->dx;
                     gb.bhitpos.y -= stmp->dy;