diff --git a/src/emu/cpu/z80/z80.c b/src/emu/cpu/z80/z80.c
index d3359479b35..9c6112843b6 100644
--- a/src/emu/cpu/z80/z80.c
+++ b/src/emu/cpu/z80/z80.c
@@ -3679,7 +3679,7 @@ static void set_irq_line(z80_state *z80, int irqline, int state)
 		/* update the IRQ state via the daisy chain */
 		z80->irq_state = state;
 		if (z80->daisy.present())
-			z80->irq_state = z80->daisy.update_irq_state();
+			z80->irq_state = ( z80->daisy.update_irq_state() == ASSERT_LINE ) ? ASSERT_LINE : z80->irq_state;
 
 		/* the main execute loop will take the interrupt */
 	}
diff --git a/src/emu/cpu/z80/z80daisy.c b/src/emu/cpu/z80/z80daisy.c
index cd0880bed77..9b789d0e38d 100644
--- a/src/emu/cpu/z80/z80daisy.c
+++ b/src/emu/cpu/z80/z80daisy.c
@@ -144,16 +144,19 @@ int z80_daisy_chain::update_irq_state()
 
 int z80_daisy_chain::call_ack_device()
 {
+	int vector = 0;
+
 	// loop over all devices; dev[0] is the highest priority
 	for (daisy_entry *daisy = m_daisy_list; daisy != NULL; daisy = daisy->m_next)
 	{
 		// if this device is asserting the INT line, that's the one we want
 		int state = daisy->m_interface->z80daisy_irq_state();
+		vector = daisy->m_interface->z80daisy_irq_ack();
 		if (state & Z80_DAISY_INT)
-			return daisy->m_interface->z80daisy_irq_ack();
+			return vector;
 	}
 	logerror("z80daisy_call_ack_device: failed to find an device to ack!\n");
-	return 0;
+	return vector;
 }