diff --git a/scst/src/dev_handlers/scst_cdrom.c b/scst/src/dev_handlers/scst_cdrom.c
index 4870ea254..7fba2c035 100644
--- a/scst/src/dev_handlers/scst_cdrom.c
+++ b/scst/src/dev_handlers/scst_cdrom.c
@@ -43,6 +43,7 @@ static int cdrom_done(struct scst_cmd *);
 static struct scst_dev_type cdrom_devtype = {
 	.name =			CDROM_NAME,
 	.type =			TYPE_ROM,
+	.threads_num =		1,
 	.parse_atomic =		1,
 	.dev_done_atomic =	1,
 	.attach =		cdrom_attach,
diff --git a/scst/src/dev_handlers/scst_changer.c b/scst/src/dev_handlers/scst_changer.c
index b0b459fad..0e88ec66e 100644
--- a/scst/src/dev_handlers/scst_changer.c
+++ b/scst/src/dev_handlers/scst_changer.c
@@ -38,6 +38,7 @@ static int changer_parse(struct scst_cmd *);
 static struct scst_dev_type changer_devtype = {
 	.name =	CHANGER_NAME,
 	.type =	TYPE_MEDIUM_CHANGER,
+	.threads_num =	1,
 	.parse_atomic =	1,
 /*	.dev_done_atomic =	1, */
 	.attach =	changer_attach,
diff --git a/scst/src/dev_handlers/scst_disk.c b/scst/src/dev_handlers/scst_disk.c
index d9b4bf0f0..044923cdd 100644
--- a/scst/src/dev_handlers/scst_disk.c
+++ b/scst/src/dev_handlers/scst_disk.c
@@ -49,6 +49,7 @@ static int disk_exec(struct scst_cmd *cmd);
 static struct scst_dev_type disk_devtype = {
 	.name =			DISK_NAME,
 	.type =			TYPE_DISK,
+	.threads_num =		1,
 	.parse_atomic =		1,
 	.dev_done_atomic =	1,
 	.attach =		disk_attach,
diff --git a/scst/src/dev_handlers/scst_modisk.c b/scst/src/dev_handlers/scst_modisk.c
index 7f1d99013..14fad5e32 100644
--- a/scst/src/dev_handlers/scst_modisk.c
+++ b/scst/src/dev_handlers/scst_modisk.c
@@ -49,6 +49,7 @@ static int modisk_exec(struct scst_cmd *);
 static struct scst_dev_type modisk_devtype = {
 	.name =			MODISK_NAME,
 	.type =			TYPE_MOD,
+	.threads_num =		1,
 	.parse_atomic =		1,
 	.dev_done_atomic =	1,
 	.attach =		modisk_attach,
diff --git a/scst/src/dev_handlers/scst_processor.c b/scst/src/dev_handlers/scst_processor.c
index 5340acec7..b178ae836 100644
--- a/scst/src/dev_handlers/scst_processor.c
+++ b/scst/src/dev_handlers/scst_processor.c
@@ -38,6 +38,7 @@ static int processor_parse(struct scst_cmd *);
 static struct scst_dev_type processor_devtype = {
 	.name =			PROCESSOR_NAME,
 	.type =			TYPE_PROCESSOR,
+	.threads_num =		1,
 	.parse_atomic =		1,
 /*	.dev_done_atomic =	1,*/
 	.attach =		processor_attach,
diff --git a/scst/src/dev_handlers/scst_raid.c b/scst/src/dev_handlers/scst_raid.c
index b403e091e..86e46f1e7 100644
--- a/scst/src/dev_handlers/scst_raid.c
+++ b/scst/src/dev_handlers/scst_raid.c
@@ -38,6 +38,7 @@ static int raid_parse(struct scst_cmd *);
 static struct scst_dev_type raid_devtype = {
 	.name =			RAID_NAME,
 	.type =			TYPE_RAID,
+	.threads_num =		1,
 	.parse_atomic =		1,
 /*	.dev_done_atomic =	1,*/
 	.attach =		raid_attach,
diff --git a/scst/src/dev_handlers/scst_tape.c b/scst/src/dev_handlers/scst_tape.c
index ee9e2e140..70b9289ae 100644
--- a/scst/src/dev_handlers/scst_tape.c
+++ b/scst/src/dev_handlers/scst_tape.c
@@ -54,6 +54,7 @@ static int tape_exec(struct scst_cmd *);
 static struct scst_dev_type tape_devtype = {
 	.name =			TAPE_NAME,
 	.type =			TYPE_TAPE,
+	.threads_num =		1,
 	.parse_atomic =		1,
 	.dev_done_atomic =	1,
 	.attach =		tape_attach,