diff --git a/src/dogmove.c b/src/dogmove.c
index fe98fa551..fb214c54e 100644
--- a/src/dogmove.c
+++ b/src/dogmove.c
@@ -406,7 +406,8 @@ dog_invent(struct monst *mtmp, struct edog *edog, int udist)
      * Use udist+1 so steed won't cause divide by zero.
      */
     if (droppables(mtmp)) {
-        if (!rn2(udist + 1) || (edog->apport && !rn2(edog->apport)))
+        assert(edog->apport > 0);
+        if (!rn2(udist + 1) || !rn2(edog->apport))
             if (rn2(10) < edog->apport) {
                 relobj(mtmp, (int) mtmp->minvis, TRUE);
                 if (edog->apport > 1)