diff --git a/src/mame/audio/nichisnd.cpp b/src/mame/audio/nichisnd.cpp
index 5235d4f9849..9a9e5169a10 100644
--- a/src/mame/audio/nichisnd.cpp
+++ b/src/mame/audio/nichisnd.cpp
@@ -88,7 +88,7 @@ MACHINE_CONFIG_START(nichisnd_device::device_add_mconfig)
 	audiocpu.out_pb_callback().set("dac1", FUNC(dac_byte_interface::data_w));
 	audiocpu.out_pc_callback().set("dac2", FUNC(dac_byte_interface::data_w));
 	audiocpu.out_pe_callback().set(FUNC(nichisnd_device::soundlatch_clear_w));
-	audiocpu.zc0_callback().set(FUNC(tmpz84c011_device::trg3));
+	audiocpu.zc0_callback().set("audiocpu", FUNC(tmpz84c011_device::trg3));
 
 	/* sound hardware */
 	SPEAKER(config, "speaker").front_center();
diff --git a/src/mame/drivers/nbmj9195.cpp b/src/mame/drivers/nbmj9195.cpp
index 0230b862896..72e5bbcca5f 100644
--- a/src/mame/drivers/nbmj9195.cpp
+++ b/src/mame/drivers/nbmj9195.cpp
@@ -2519,7 +2519,7 @@ MACHINE_CONFIG_START(nbmj9195_state::NBMJDRV1_base)
 	audiocpu.set_daisy_config(daisy_chain_sound);
 	audiocpu.set_addrmap(AS_PROGRAM, &nbmj9195_state::sailorws_sound_map);
 	audiocpu.set_addrmap(AS_IO, &nbmj9195_state::sailorws_sound_io_map);
-	audiocpu.zc0_callback().set(FUNC(tmpz84c011_device::trg3));
+	audiocpu.zc0_callback().set("audiocpu", FUNC(tmpz84c011_device::trg3));
 	audiocpu.out_pa_callback().set(FUNC(nbmj9195_state::soundbank_w));
 	audiocpu.out_pb_callback().set("dac1", FUNC(dac_byte_interface::data_w));
 	audiocpu.out_pc_callback().set("dac2", FUNC(dac_byte_interface::data_w));