diff --git a/net/batman-adv/aggregation.c b/net/batman-adv/aggregation.c
index c583e049f421..69467fe71ff2 100644
--- a/net/batman-adv/aggregation.c
+++ b/net/batman-adv/aggregation.c
@@ -28,6 +28,7 @@
 
 /* return true if new_packet can be aggregated with forw_packet */
 static bool can_aggregate_with(const struct batman_packet *new_batman_packet,
+			       struct bat_priv *bat_priv,
 			       int packet_len,
 			       unsigned long send_time,
 			       bool directlink,
@@ -37,6 +38,8 @@ static bool can_aggregate_with(const struct batman_packet *new_batman_packet,
 	struct batman_packet *batman_packet =
 		(struct batman_packet *)forw_packet->skb->data;
 	int aggregated_bytes = forw_packet->packet_len + packet_len;
+	struct hard_iface *primary_if = NULL;
+	bool res = false;
 
 	/**
 	 * we can aggregate the current packet to this aggregated packet
@@ -61,6 +64,10 @@ static bool can_aggregate_with(const struct batman_packet *new_batman_packet,
 		 *    packet
 		 */
 
+		primary_if = primary_if_get_selected(bat_priv);
+		if (!primary_if)
+			goto out;
+
 		/* packets without direct link flag and high TTL
 		 * are flooded through the net  */
 		if ((!directlink) &&
@@ -70,8 +77,10 @@ static bool can_aggregate_with(const struct batman_packet *new_batman_packet,
 		    /* own packets originating non-primary
 		     * interfaces leave only that interface */
 		    ((!forw_packet->own) ||
-		     (forw_packet->if_incoming->if_num == 0)))
-			return true;
+		     (forw_packet->if_incoming == primary_if))) {
+			res = true;
+			goto out;
+		}
 
 		/* if the incoming packet is sent via this one
 		 * interface only - we still can aggregate */
@@ -84,11 +93,16 @@ static bool can_aggregate_with(const struct batman_packet *new_batman_packet,
 		     * (= secondary interface packets in general) */
 		    (batman_packet->flags & DIRECTLINK ||
 		     (forw_packet->own &&
-		      forw_packet->if_incoming->if_num != 0)))
-			return true;
+		      forw_packet->if_incoming != primary_if))) {
+			res = true;
+			goto out;
+		}
 	}
 
-	return false;
+out:
+	if (primary_if)
+		hardif_free_ref(primary_if);
+	return res;
 }
 
 /* create a new aggregated packet and add this packet to it */
@@ -210,6 +224,7 @@ void add_bat_packet_to_list(struct bat_priv *bat_priv,
 		hlist_for_each_entry(forw_packet_pos, tmp_node,
 				     &bat_priv->forw_bat_list, list) {
 			if (can_aggregate_with(batman_packet,
+					       bat_priv,
 					       packet_len,
 					       send_time,
 					       direct_link,