diff --git a/src/emu/diexec.h b/src/emu/diexec.h
index 23fd46cf21b..2381b2d8172 100644
--- a/src/emu/diexec.h
+++ b/src/emu/diexec.h
@@ -114,7 +114,7 @@ typedef device_delegate<void (device_t &)> device_interrupt_delegate;
 
 // IRQ callback to be called by executing devices when an IRQ is actually taken
 typedef device_delegate<int (device_t &, int)> device_irq_acknowledge_delegate;
-/*ATTR_DEPRECATED*/ typedef int (*device_irq_acknowledge_callback)(device_t *device, int irqnum);
+ATTR_DEPRECATED typedef int (*device_irq_acknowledge_callback)(device_t *device, int irqnum);