diff --git a/src/emu/diexec.cpp b/src/emu/diexec.cpp
index 972c3ecdf96..c7f4752bd6d 100644
--- a/src/emu/diexec.cpp
+++ b/src/emu/diexec.cpp
@@ -345,13 +345,12 @@ void device_execute_interface::execute_set_input(int linenum, int state)
 void device_execute_interface::interface_validity_check(validity_checker &valid) const
 {
 	// validate the interrupts
-	if (!m_vblank_interrupt.isnull())
+	if (!m_vblank_interrupt_screen)
 	{
-		screen_device_iterator iter(device().mconfig().root_device());
-		if (iter.first() == nullptr)
-			osd_printf_error("VBLANK interrupt specified, but the driver is screenless\n");
-		else if (m_vblank_interrupt_screen == nullptr)
-			osd_printf_error("VBLANK interrupt references a non-existant screen tag\n");
+		if (m_vblank_interrupt_screen.finder_tag() != finder_base::DUMMY_TAG)
+			osd_printf_error("VBLANK interrupt references non-existent screen tag %s\n", m_vblank_interrupt_screen.finder_tag());
+		else if (!m_vblank_interrupt.isnull())
+			osd_printf_error("VBLANK interrupt specified, but no screen configured\n");
 	}
 
 	if (!m_timed_interrupt.isnull() && m_timed_interrupt_period == attotime::zero)
@@ -444,9 +443,7 @@ void device_execute_interface::interface_post_reset()
 
 	// reconfingure VBLANK interrupts
 	if (m_vblank_interrupt_screen)
-	{
 		m_vblank_interrupt_screen->register_vblank_callback(vblank_state_delegate(&device_execute_interface::on_vblank, this));
-	}
 
 	// reconfigure periodic interrupts
 	if (m_timed_interrupt_period != attotime::zero)
diff --git a/src/emu/diexec.h b/src/emu/diexec.h
index 3c1e17bd156..597f3186174 100644
--- a/src/emu/diexec.h
+++ b/src/emu/diexec.h
@@ -86,7 +86,7 @@ enum
 #define MCFG_DEVICE_VBLANK_INT_DEVICE(_tag, _devtag, _class, _func) \
 	dynamic_cast<device_execute_interface &>(*device).set_vblank_int(device_interrupt_delegate(&_class::_func, #_class "::" #_func, _devtag, (_class *)nullptr), _tag);
 #define MCFG_DEVICE_VBLANK_INT_REMOVE()  \
-	dynamic_cast<device_execute_interface &>(*device).set_vblank_int(device_interrupt_delegate(), nullptr);
+	dynamic_cast<device_execute_interface &>(*device).set_vblank_int(device_interrupt_delegate(), finder_base::DUMMY_TAG);
 #define MCFG_DEVICE_PERIODIC_INT_DRIVER(_class, _func, _rate) \
 	dynamic_cast<device_execute_interface &>(*device).set_periodic_int(device_interrupt_delegate(&_class::_func, #_class "::" #_func, DEVICE_SELF, (_class *)nullptr), attotime::from_hz(_rate));
 #define MCFG_DEVICE_PERIODIC_INT_DEVICE(_devtag, _class, _func, _rate) \
diff --git a/src/emu/screen.cpp b/src/emu/screen.cpp
index 6434419c761..00a1a6435e7 100644
--- a/src/emu/screen.cpp
+++ b/src/emu/screen.cpp
@@ -630,12 +630,13 @@ void screen_device::device_validity_check(validity_checker &valid) const
 		osd_printf_error("Invalid (zero) refresh rate\n");
 
 	texture_format texformat = !m_screen_update_ind16.isnull() ? TEXFORMAT_PALETTE16 : TEXFORMAT_RGB32;
-	if (m_palette != nullptr)
+	if (m_palette.finder_tag() != finder_base::DUMMY_TAG)
 	{
+		if (!m_palette)
+			osd_printf_error("Screen references non-existent palette tag %s\n", m_palette.finder_tag());
+
 		if (texformat == TEXFORMAT_RGB32)
-		{
 			osd_printf_warning("Screen does not need palette defined\n");
-		}
 	}
 	else if (texformat == TEXFORMAT_PALETTE16)
 	{
@@ -659,9 +660,7 @@ void screen_device::device_resolve_objects()
 
 	// assign our format to the palette before it starts
 	if (m_palette)
-	{
 		m_palette->m_format = format();
-	}
 }
 
 
@@ -689,7 +688,7 @@ void screen_device::device_start()
 	}
 
 	// if we have a palette and it's not started, wait for it
-	if (m_palette != nullptr && !m_palette->device().started())
+	if (m_palette && !m_palette->device().started())
 		throw device_missing_dependencies();
 
 	// configure bitmap formats and allocate screen bitmaps
@@ -962,7 +961,7 @@ void screen_device::realloc_screen_bitmaps()
 		item->m_bitmap.resize(effwidth, effheight);
 
 	// re-set up textures
-	if (m_palette != nullptr)
+	if (m_palette)
 	{
 		m_bitmap[0].set_palette(m_palette->palette());
 		m_bitmap[1].set_palette(m_palette->palette());
@@ -1334,7 +1333,7 @@ void screen_device::register_screen_bitmap(bitmap_t &bitmap)
 
 	// if allocating now, just do it
 	bitmap.allocate(width(), height());
-	if (m_palette != nullptr)
+	if (m_palette)
 		bitmap.set_palette(m_palette->palette());
 }
 
diff --git a/src/emu/screen.h b/src/emu/screen.h
index 508c0756e37..37aaccbfabc 100644
--- a/src/emu/screen.h
+++ b/src/emu/screen.h
@@ -309,7 +309,7 @@ private:
 	screen_update_ind16_delegate m_screen_update_ind16; // screen update callback (16-bit palette)
 	screen_update_rgb32_delegate m_screen_update_rgb32; // screen update callback (32-bit RGB)
 	devcb_write_line    m_screen_vblank;            // screen vblank line callback
-	optional_device<palette_device> m_palette;      // our palette
+	optional_device<device_palette_interface> m_palette;      // our palette
 	u32                 m_video_attributes;         // flags describing the video system
 	const char *        m_svg_region;               // the region in which the svg data is in