diff --git a/yasnd.c b/yasnd.c
index 5324706..964459f 100644
--- a/yasnd.c
+++ b/yasnd.c
@@ -139,6 +139,22 @@ void check_host(int num,host_decl* host)
 	host->helper_pid=pid;
 }
 
+/*
+	Function, that turn on first LPT port pin and turn off others.
+	This is needed to lock LPT control circuit, when
+	management computer is rebooted
+*/
+void lpt_lock()
+{
+	if (ioperm (lpt_port, 3, 1))
+	{
+		log_event("Error: LPT port access error");
+		exit(EXIT_FAILURE);
+	}
+	// Lock circuit
+	outb (1, lpt_port);
+}
+
 /*
 	Function, that turn on only one LPT port pin, defined by it argument, wait a second,
 	and turn off all pins. That is enough to reset specified host.
@@ -248,6 +264,9 @@ void signal_handler(int signum)
 	if (signum==SIGTERM)
 	{
 		log_event("SIGTERM captured, daemon stopping");
+		// block LPT control circuit
+		if (lpt_enable)
+			lpt_lock();
 		// close log decriptor
 		closelog();
 		// free resources