diff --git a/src/mame/drivers/hp700.cpp b/src/mame/drivers/hp700.cpp
index 6a3d2b3a29d..942b641ed8f 100644
--- a/src/mame/drivers/hp700.cpp
+++ b/src/mame/drivers/hp700.cpp
@@ -47,6 +47,7 @@ static MACHINE_CONFIG_START( hp700_92 )
 	MCFG_NVRAM_ADD_0FILL("nvram")
 
 	MCFG_DEVICE_ADD("duart", SCN2681, XTAL_29_4912MHz / 8) // divider not verified
+	MCFG_MC68681_IRQ_CALLBACK(INPUTLINE("maincpu", INPUT_LINE_IRQ0))
 MACHINE_CONFIG_END