diff --git a/gossipd/broadcast.c b/gossipd/broadcast.c
index 93febfcd4..2afdc39ab 100644
--- a/gossipd/broadcast.c
+++ b/gossipd/broadcast.c
@@ -71,7 +71,7 @@ bool queue_broadcast(struct broadcast_state *bstate,
 	/* Now add the message to the queue */
 	msg = new_queued_message(bstate, type, tag, payload);
 	uintmap_add(&bstate->broadcasts, bstate->next_index, msg);
-	bstate->next_index += 1;
+	bstate->next_index++;
 	return evicted;
 }
 
diff --git a/gossipd/broadcast.h b/gossipd/broadcast.h
index 296b03a7f..49094763e 100644
--- a/gossipd/broadcast.h
+++ b/gossipd/broadcast.h
@@ -20,7 +20,7 @@ struct queued_message {
 };
 
 struct broadcast_state {
-	u32 next_index;
+	u64 next_index;
 	UINTMAP(struct queued_message *) broadcasts;
 };