diff --git a/src/scsi/scsi_aha154x.c b/src/scsi/scsi_aha154x.c
index e3c2ca3d5..e234da639 100644
--- a/src/scsi/scsi_aha154x.c
+++ b/src/scsi/scsi_aha154x.c
@@ -268,10 +268,7 @@ aha_fast_cmds(void *p, uint8_t cmd)
     if (cmd == CMD_BIOS_SCSI) {
 	x54x_busy(1);
 	dev->BIOSMailboxReq++;
-
-#if 0
-	x54x_thread_start(dev);
-#endif
+	x54x_set_wait_event();
 	x54x_busy(0);
 	return 1;
     }
diff --git a/src/scsi/scsi_x54x.c b/src/scsi/scsi_x54x.c
index 926945ad1..417633e04 100644
--- a/src/scsi/scsi_x54x.c
+++ b/src/scsi/scsi_x54x.c
@@ -57,6 +57,8 @@ int	busy;
 
 static volatile
 event_t	*evt;
+static volatile
+event_t	*wait_evt;
 
 static volatile
 event_t	*wake_poll_thread;
@@ -1318,7 +1320,7 @@ x54x_cmd_thread(void *priv)
 
 	if ((dev->Status & STAT_INIT) || (!dev->MailboxInit && !dev->BIOSMailboxInit) || (!dev->MailboxReq && !dev->BIOSMailboxReq)) {
 		/* If we did not get anything, wait a while. */
-		thread_wait_event((event_t *) evt, 10);
+		thread_wait_event((event_t *) wait_evt, 10);
 
 		scsi_mutex_wait(0);
 		continue;
@@ -1368,6 +1370,13 @@ x54x_is_busy(void)
 }
 
 
+void
+x54x_set_wait_event(void)
+{
+    thread_set_event((event_t *) wait_evt);
+}
+
+
 static uint8_t
 x54x_in(uint16_t port, void *priv)
 {
@@ -1537,6 +1546,7 @@ x54x_out(uint16_t port, uint8_t val, void *priv)
 		if ((val == CMD_START_SCSI) && (dev->Command == 0xff)) {
 			x54x_busy(1);
 			dev->MailboxReq++;
+			x54x_set_wait_event();
 			x54x_log("Start SCSI command: ");
 			x54x_busy(0);
 			return;
@@ -1969,6 +1979,7 @@ x54x_init(device_t *info)
 
     /* Create a waitable event. */
     evt = thread_create_event();
+    wait_evt = thread_create_event();
 
     x54x_thread_start(dev);
     thread_wait_event((event_t *) thread_started, -1);
@@ -2005,6 +2016,11 @@ x54x_close(void *priv)
 	if (dev->ven_data)
 		free(dev->ven_data);
 
+	if (wait_evt) {
+		thread_destroy_event((event_t *) evt);
+		evt = NULL;
+	}
+
 	if (evt) {
 		thread_destroy_event((event_t *) evt);
 		evt = NULL;
diff --git a/src/scsi/scsi_x54x.h b/src/scsi/scsi_x54x.h
index 86b1ffde0..9f850f162 100644
--- a/src/scsi/scsi_x54x.h
+++ b/src/scsi/scsi_x54x.h
@@ -494,6 +494,7 @@ typedef struct
 extern void	x54x_reset_ctrl(x54x_t *dev, uint8_t Reset);
 extern void	x54x_busy(uint8_t set);
 extern void	x54x_thread_start(x54x_t *dev);
+extern void	x54x_set_wait_event(void);
 extern uint8_t	x54x_is_busy(void);
 extern void	x54x_buf_alloc(uint8_t id, uint8_t lun, int length);
 extern void	x54x_buf_free(uint8_t id, uint8_t lun);