diff --git a/src/mame/drivers/maygay1b.cpp b/src/mame/drivers/maygay1b.cpp
index e8d95836dcf..143de6d02df 100644
--- a/src/mame/drivers/maygay1b.cpp
+++ b/src/mame/drivers/maygay1b.cpp
@@ -769,7 +769,7 @@ ADDRESS_MAP_END
 
 MACHINE_CONFIG_START( maygay_m1 )
 
-	MCFG_CPU_ADD("maincpu", M6809, M1_MASTER_CLOCK/2)
+	MCFG_CPU_ADD("maincpu", MC6809, M1_MASTER_CLOCK/2) // claimed to be 4 MHz
 	MCFG_CPU_PROGRAM_MAP(m1_memmap)
 
 	MCFG_CPU_ADD("mcu", I80C51, 2000000) //  EP840034.A-P-80C51AVW