diff --git a/src/mame/audio/seibu.c b/src/mame/audio/seibu.c
index a74cedc1df9..2d9d86bfb79 100644
--- a/src/mame/audio/seibu.c
+++ b/src/mame/audio/seibu.c
@@ -338,6 +338,9 @@ MACHINE_RESET( seibu_sound )
 	update_irq_lines(machine, VECTOR_INIT);
 	if (romlength > 0x10000)
 		memory_configure_bank(machine, "bank1", 0, (romlength - 0x10000) / 0x8000, rom + 0x10000, 0x8000);
+
+	/* Denjin Makai definitely needs this at start-up, it never writes to the bankswitch */
+	memory_set_bank(machine, "bank1", 0);
 }
 
 /***************************************************************************/
@@ -406,7 +409,7 @@ WRITE16_HANDLER( seibu_main_word_w )
 				main2sub[offset] = data;
 				break;
 			case 4:
-				if (strcmp(space->machine->gamedrv->name, "sdgndmps") == 0)
+				if (strcmp(space->machine->gamedrv->name, "sdgndmps") == 0 || strcmp(space->machine->gamedrv->name, "denjinmk") == 0)
 					update_irq_lines(space->machine, RST10_ASSERT);
 				update_irq_lines(space->machine, RST18_ASSERT);
 				break;