diff --git a/source/libsmb/clitrans.c b/source/libsmb/clitrans.c
index f43a2aa..441f5a0 100644
--- a/source/libsmb/clitrans.c
+++ b/source/libsmb/clitrans.c
@@ -95,9 +95,14 @@ BOOL cli_send_trans(struct cli_state *cli, int trans,
 		return False;
 	}
 
+	/* Note we're in a trans state. Save the sequence
+	 * numbers for replies. */
+	client_set_trans_sign_state_on(cli, mid);
+
 	if (this_ldata < ldata || this_lparam < lparam) {
 		/* receive interim response */
 		if (!cli_receive_smb(cli) || cli_is_error(cli)) {
+			client_set_trans_sign_state_off(cli, mid);
 			return(False);
 		}
 
@@ -108,6 +113,9 @@ BOOL cli_send_trans(struct cli_state *cli, int trans,
 			this_lparam = MIN(lparam-tot_param,cli->max_xmit - 500); /* hack */
 			this_ldata = MIN(ldata-tot_data,cli->max_xmit - (500+this_lparam));
 
+			client_set_trans_sign_state_off(cli, mid);
+			client_set_trans_sign_state_on(cli, mid);
+
 			set_message(cli->outbuf,trans==SMBtrans?8:9,0,True);
 			SCVAL(cli->outbuf,smb_com,(trans==SMBtrans ? SMBtranss : SMBtranss2));
 			
@@ -139,6 +147,7 @@ BOOL cli_send_trans(struct cli_state *cli, int trans,
 
 			show_msg(cli->outbuf);
 			if (!cli_send_smb(cli)) {
+				client_set_trans_sign_state_off(cli, mid);
 				return False;
 			}
 
@@ -317,6 +326,7 @@ BOOL cli_receive_trans(struct cli_state *cli,int trans,
 
   out:
 
+	client_set_trans_sign_state_off(cli, SVAL(cli->inbuf,smb_mid));
 	return ret;
 }
 
@@ -384,9 +394,14 @@ BOOL cli_send_nt_trans(struct cli_state *cli,
 		return False;
 	}	
 
+	/* Note we're in a trans state. Save the sequence
+	 * numbers for replies. */
+	client_set_trans_sign_state_on(cli, mid);
+
 	if (this_ldata < ldata || this_lparam < lparam) {
 		/* receive interim response */
 		if (!cli_receive_smb(cli) || cli_is_error(cli)) {
+			client_set_trans_sign_state_off(cli, mid);
 			return(False);
 		}
 
@@ -428,6 +443,7 @@ BOOL cli_send_nt_trans(struct cli_state *cli,
 			show_msg(cli->outbuf);
 
 			if (!cli_send_smb(cli)) {
+				client_set_trans_sign_state_off(cli, mid);
 				return False;
 			}
 			
@@ -627,5 +643,6 @@ BOOL cli_receive_nt_trans(struct cli_state *cli,
 
   out:
 
+	client_set_trans_sign_state_off(cli, SVAL(cli->inbuf,smb_mid));
 	return ret;
 }
diff --git a/source/libsmb/smb_signing.c b/source/libsmb/smb_signing.c
index 6768c2a..df74b2d 100644
--- a/source/libsmb/smb_signing.c
+++ b/source/libsmb/smb_signing.c
@@ -26,6 +26,7 @@ struct outstanding_packet_lookup {
 	struct outstanding_packet_lookup *prev, *next;
 	uint16 mid;
 	uint32 reply_seq_num;
+	BOOL can_delete; /* Set to False in trans state. */
 };
 
 struct smb_basic_signing_context {
@@ -42,9 +43,7 @@ static BOOL store_sequence_for_reply(struct outstanding_packet_lookup **list,
 	/* Ensure we only add a mid once. */
 	for (t = *list; t; t = t->next) {
 		if (t->mid == mid) {
-			DLIST_REMOVE(*list, t);
-			SAFE_FREE(t);
-			break;
+			return False;
 		}
 	}
 
@@ -53,6 +52,7 @@ static BOOL store_sequence_for_reply(struct outstanding_packet_lookup **list,
 
 	t->mid = mid;
 	t->reply_seq_num = reply_seq_num;
+	t->can_delete = True;
 
 	/*
 	 * Add to the *start* of the list not the end of the list.
@@ -79,8 +79,23 @@ static BOOL get_sequence_for_reply(struct outstanding_packet_lookup **list,
 			*reply_seq_num = t->reply_seq_num;
 			DEBUG(10,("get_sequence_for_reply: found seq = %u mid = %u\n",
 				(unsigned int)t->reply_seq_num, (unsigned int)t->mid ));
-			DLIST_REMOVE(*list, t);
-			SAFE_FREE(t);
+			if (t->can_delete) {
+				DLIST_REMOVE(*list, t);
+				SAFE_FREE(t);
+			}
+			return True;
+		}
+	}
+	return False;
+}
+
+static BOOL set_sequence_can_delete_flag(struct outstanding_packet_lookup **list, uint16 mid, BOOL can_delete_entry)
+{
+	struct outstanding_packet_lookup *t;
+
+	for (t = *list; t; t = t->next) {
+		if (t->mid == mid) {
+			t->can_delete = can_delete_entry;
 			return True;
 		}
 	}
@@ -589,6 +604,60 @@ BOOL cli_check_sign_mac(struct cli_state *cli)
 }
 
 /***********************************************************
+ Enter trans/trans2/nttrans state.
+************************************************************/
+
+BOOL client_set_trans_sign_state_on(struct cli_state *cli, uint16 mid)
+{
+	struct smb_sign_info *si = &cli->sign_info;
+	struct smb_basic_signing_context *data = (struct smb_basic_signing_context *)si->signing_context;
+
+	if (!si->doing_signing) {
+		return True;
+	}
+
+	if (!data) {
+		return False;
+	}
+
+	if (!set_sequence_can_delete_flag(&data->outstanding_packet_list, mid, False)) {
+		return False;
+	}
+
+	return True;
+}
+
+/***********************************************************
+ Leave trans/trans2/nttrans state.
+************************************************************/
+
+BOOL client_set_trans_sign_state_off(struct cli_state *cli, uint16 mid)
+{
+	uint32 reply_seq_num;
+	struct smb_sign_info *si = &cli->sign_info;
+	struct smb_basic_signing_context *data = (struct smb_basic_signing_context *)si->signing_context;
+
+	if (!si->doing_signing) {
+		return True;
+	}
+
+	if (!data) {
+		return False;
+	}
+
+	if (!set_sequence_can_delete_flag(&data->outstanding_packet_list, mid, True)) {
+		return False;
+	}
+
+	/* Now delete the stored mid entry. */
+	if (!get_sequence_for_reply(&data->outstanding_packet_list, mid, &reply_seq_num)) {
+		return False;
+	}
+
+	return True;
+}
+
+/***********************************************************
  SMB signing - Server implementation - send the MAC.
 ************************************************************/