diff --git a/scst/src/scst_copy_mgr.c b/scst/src/scst_copy_mgr.c
index b991f74a5..cba7f11ce 100644
--- a/scst/src/scst_copy_mgr.c
+++ b/scst/src/scst_copy_mgr.c
@@ -2676,13 +2676,15 @@ out:
 
 void scst_cm_update_dev(struct scst_device *dev)
 {
-	int rc;
+	int rc, res;
 
 	TRACE_ENTRY();
 
 	TRACE_MGMT_DBG("copy manager: updating device %s", dev->virt_name);
 
-	scst_suspend_activity(SCST_SUSPEND_TIMEOUT_UNLIMITED);
+	res = scst_suspend_activity(SCST_SUSPEND_TIMEOUT_UNLIMITED);
+	WARN_ON_ONCE(res);
+
 	mutex_lock(&scst_mutex);
 
 	scst_cm_dev_unregister(dev, false);
diff --git a/scst/src/scst_main.c b/scst/src/scst_main.c
index 6f2f2173b..3154c9c75 100644
--- a/scst/src/scst_main.c
+++ b/scst/src/scst_main.c
@@ -560,6 +560,7 @@ void scst_unregister_target(struct scst_tgt *tgt)
 {
 	struct scst_tgt_template *vtt = tgt->tgtt;
 	struct scst_acg *acg, *acg_tmp;
+	int res;
 
 	TRACE_ENTRY();
 
@@ -612,7 +613,9 @@ again:
 	wait_event(tgt->unreg_waitQ, list_empty(&tgt->sysfs_sess_list));
 	TRACE_DBG("%s", "wait_event() returned");
 
-	scst_suspend_activity(SCST_SUSPEND_TIMEOUT_UNLIMITED);
+	res = scst_suspend_activity(SCST_SUSPEND_TIMEOUT_UNLIMITED);
+	WARN_ON_ONCE(res);
+
 	mutex_lock(&scst_mutex);
 
 	mutex_lock(&scst_mutex2);
@@ -1584,11 +1587,13 @@ void scst_unregister_dev_driver(struct scst_dev_type *dev_type)
 {
 	struct scst_device *dev;
 	struct scst_dev_type *dt;
-	int found = 0;
+	int res, found = 0;
 
 	TRACE_ENTRY();
 
-	scst_suspend_activity(SCST_SUSPEND_TIMEOUT_UNLIMITED);
+	res = scst_suspend_activity(SCST_SUSPEND_TIMEOUT_UNLIMITED);
+	WARN_ON_ONCE(res);
+
 	mutex_lock(&scst_mutex);
 
 	list_for_each_entry(dt, &scst_dev_type_list, dev_type_list_entry) {