diff --git a/net/batman-adv/fragmentation.c b/net/batman-adv/fragmentation.c
index af495cc861fe..a9fc6537214b 100644
--- a/net/batman-adv/fragmentation.c
+++ b/net/batman-adv/fragmentation.c
@@ -161,6 +161,7 @@ static bool batadv_frag_insert_packet(struct batadv_orig_node *orig_node,
 		hlist_add_head(&frag_entry_new->list, &chain->head);
 		chain->size = skb->len - hdr_size;
 		chain->timestamp = jiffies;
+		chain->total_size = ntohs(frag_packet->total_size);
 		ret = true;
 		goto out;
 	}
@@ -195,9 +196,11 @@ static bool batadv_frag_insert_packet(struct batadv_orig_node *orig_node,
 
 out:
 	if (chain->size > batadv_frag_size_limit() ||
-	    ntohs(frag_packet->total_size) > batadv_frag_size_limit()) {
+	    chain->total_size != ntohs(frag_packet->total_size) ||
+	    chain->total_size > batadv_frag_size_limit()) {
 		/* Clear chain if total size of either the list or the packet
-		 * exceeds the maximum size of one merged packet.
+		 * exceeds the maximum size of one merged packet. Don't allow
+		 * packets to have different total_size.
 		 */
 		batadv_frag_clear_chain(&chain->head);
 		chain->size = 0;
diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h
index 28f2461ea630..e95db4273356 100644
--- a/net/batman-adv/types.h
+++ b/net/batman-adv/types.h
@@ -132,6 +132,7 @@ struct batadv_orig_ifinfo {
  * @timestamp: time (jiffie) of last received fragment
  * @seqno: sequence number of the fragments in the list
  * @size: accumulated size of packets in list
+ * @total_size: expected size of the assembled packet
  */
 struct batadv_frag_table_entry {
 	struct hlist_head head;
@@ -139,6 +140,7 @@ struct batadv_frag_table_entry {
 	unsigned long timestamp;
 	uint16_t seqno;
 	uint16_t size;
+	uint16_t total_size;
 };
 
 /**