diff --git a/src/mame/drivers/sm7238.cpp b/src/mame/drivers/sm7238.cpp
index 4c99418ccf4..609d984f36c 100644
--- a/src/mame/drivers/sm7238.cpp
+++ b/src/mame/drivers/sm7238.cpp
@@ -364,7 +364,7 @@ void sm7238_state::sm7238(machine_config &config)
 {
 	I8080(config, m_maincpu, 16.5888_MHz_XTAL/9);
 	m_maincpu->set_addrmap(AS_PROGRAM, &sm7238_state::sm7238_mem);
-	m_maincpu->set_addrmap(AS_PROGRAM, &sm7238_state::sm7238_io);
+	m_maincpu->set_addrmap(AS_IO, &sm7238_state::sm7238_io);
 	m_maincpu->set_irq_acknowledge_callback("pic8259", FUNC(pic8259_device::inta_cb));
 
 	ADDRESS_MAP_BANK(config, "videobank").set_map(&sm7238_state::videobank_map).set_options(ENDIANNESS_LITTLE, 8, 32, 0x2000);