diff --git a/src/mess/drivers/px4.c b/src/mess/drivers/px4.c
index 32c1f8797ef..4adb77446ef 100644
--- a/src/mess/drivers/px4.c
+++ b/src/mess/drivers/px4.c
@@ -590,7 +590,8 @@ WRITE8_MEMBER( px4_state::sior_w )
 	// writing clock?
 	if (m_clock_state > 0)
 	{
-		struct tm *t = localtime((const long int *)&m_time.time);
+		time_t time = m_time.time;
+		struct tm *t = localtime(&time);
 
 		switch (m_clock_state++)
 		{