diff --git a/src/include/ipxe/iscsi.h b/src/include/ipxe/iscsi.h
index e711459c..4890bcc6 100644
--- a/src/include/ipxe/iscsi.h
+++ b/src/include/ipxe/iscsi.h
@@ -539,6 +539,12 @@ struct iscsi_session {
 	/** CHAP response (used for both initiator and target auth) */
 	struct chap_response chap;
 
+	/** Initiator session ID (IANA format) qualifier
+	 *
+	 * This is part of the ISID.  It is generated randomly
+	 * whenever a new connection is opened.
+	 */
+	uint16_t isid_iana_qual;
 	/** Initiator task tag
 	 *
 	 * This is the tag of the current command.  It is incremented
diff --git a/src/net/tcp/iscsi.c b/src/net/tcp/iscsi.c
index a483dd40..5e003a81 100644
--- a/src/net/tcp/iscsi.c
+++ b/src/net/tcp/iscsi.c
@@ -246,6 +246,9 @@ static int iscsi_open_connection ( struct iscsi_session *iscsi ) {
 	if ( iscsi->target_username )
 		iscsi->status |= ISCSI_STATUS_AUTH_REVERSE_REQUIRED;
 
+	/* Assign new ISID */
+	iscsi->isid_iana_qual = ( random() & 0xffff );
+
 	/* Assign fresh initiator task tag */
 	iscsi_new_itt ( iscsi );
 
@@ -707,7 +710,7 @@ static void iscsi_start_login ( struct iscsi_session *iscsi ) {
 	ISCSI_SET_LENGTHS ( request->lengths, 0, len );
 	request->isid_iana_en = htonl ( ISCSI_ISID_IANA |
 					IANA_EN_FEN_SYSTEMS );
-	request->isid_iana_qual = ( random() & 0xffff );
+	request->isid_iana_qual = htons ( iscsi->isid_iana_qual );
 	/* tsih left as zero */
 	request->itt = htonl ( iscsi->itt );
 	/* cid left as zero */