diff --git a/src/mame/machine/deco_irq.cpp b/src/mame/machine/deco_irq.cpp
index 7ed3a210205..730bac4f3d1 100644
--- a/src/mame/machine/deco_irq.cpp
+++ b/src/mame/machine/deco_irq.cpp
@@ -93,7 +93,7 @@ TIMER_CALLBACK_MEMBER( deco_irq_device::scanline_callback )
 	uint16_t y = m_screen->vpos();
 
 	// raster irq?
-	if (m_raster_irq_scanline > 0 && m_raster_irq_scanline < 240 && y == (m_raster_irq_scanline - 1))
+	if (m_raster_irq_scanline >= visible.top() && m_raster_irq_scanline <= visible.bottom() && y == (m_raster_irq_scanline - 1))
 	{
 		if (!m_raster_irq_masked)
 		{