diff --git a/scst/src/scst_targ.c b/scst/src/scst_targ.c
index bee0ae2de..aa5c563b0 100644
--- a/scst/src/scst_targ.c
+++ b/scst/src/scst_targ.c
@@ -338,6 +338,8 @@ bool scst_do_check_blocked_dev(struct scst_cmd *cmd)
 
 	TRACE_ENTRY();
 
+	lockdep_assert_held(&dev->dev_lock);
+
 	/*
 	 * We want to have fairness between just unblocked previously blocked
 	 * SCSI atomic cmds and new cmds came after them. Otherwise, the new
@@ -482,6 +484,8 @@ void __scst_check_unblock_dev(struct scst_cmd *cmd)
 
 	TRACE_ENTRY();
 
+	lockdep_assert_held(&dev->dev_lock);
+
 	/*
 	 * We might be called here as part of Copy Manager's check blocking
 	 * undo, so restore all flags in the previous state to allow