diff --git a/include/extern.h b/include/extern.h
index 8a8bfce3f..cd0613e01 100644
--- a/include/extern.h
+++ b/include/extern.h
@@ -1239,7 +1239,7 @@ extern Loot *sortloot(struct obj **, unsigned, boolean,
                       boolean(*)(struct obj *)) NONNULLARG1;
 extern void unsortloot(Loot **) NONNULLARG1;
 extern void assigninvlet(struct obj *) NONNULLARG1;
-extern struct obj *merge_choice(struct obj *, struct obj *) NONNULLPTRS;
+extern struct obj *merge_choice(struct obj *, struct obj *) NONNULLARG2;
 extern int merged(struct obj **, struct obj **) NONNULLPTRS;
 extern void addinv_core1(struct obj *) NONNULLARG1;
 extern void addinv_core2(struct obj *) NONNULLARG1;
diff --git a/src/invent.c b/src/invent.c
index 20a7cf645..a2e99233e 100644
--- a/src/invent.c
+++ b/src/invent.c
@@ -786,6 +786,8 @@ merge_choice(struct obj *objlist, struct obj *obj)
     struct monst *shkp;
     unsigned save_nocharge;
 
+    if (!objlist) /* might be checking 'obj' against empty inventory */
+        return (struct obj *) 0;
     if (obj->otyp == SCR_SCARE_MONSTER) /* punt on these */
         return (struct obj *) 0;
     /* if this is an item on the shop floor, the attributes it will