diff --git a/src/emu/addrmap.h b/src/emu/addrmap.h
index 5a256c735fe..03d325f2372 100644
--- a/src/emu/addrmap.h
+++ b/src/emu/addrmap.h
@@ -231,35 +231,77 @@ public:
 	// device finder -> delegate converter
 	template <typename T, bool Reqd, typename U, typename Ret, typename... Params>
 	address_map_entry &r(device_finder<T, Reqd> &finder, Ret (U::*read)(Params...), const char *read_name)
-	{ const std::pair<device_t &, const char *> target(finder.finder_target()); device_t &device(*target.first.subdevice(target.second)); return r(emu::detail::make_delegate(read, read_name, device.tag(), make_pointer<U>(device))); }
+	{
+		const std::pair<device_t &, const char *> target(finder.finder_target());
+		device_t *device(target.first.subdevice(target.second));
+		assert(device != nullptr);
+		return r(emu::detail::make_delegate(read, read_name, device->tag(), make_pointer<U>(*device)));
+	}
 
 	template <typename T, bool Reqd, typename U, typename Ret, typename... Params>
 	address_map_entry &r(const device_finder<T, Reqd> &finder, Ret (U::*read)(Params...), const char *read_name)
-	{ const std::pair<device_t &, const char *> target(finder.finder_target()); device_t &device(*target.first.subdevice(target.second)); return r(emu::detail::make_delegate(read, read_name, device.tag(), make_pointer<U>(device))); }
+	{
+		const std::pair<device_t &, const char *> target(finder.finder_target());
+		device_t *device(target.first.subdevice(target.second));
+		assert(device != nullptr);
+		return r(emu::detail::make_delegate(read, read_name, device->tag(), make_pointer<U>(*device)));
+	}
 
 	template <typename T, bool Reqd, typename U, typename Ret, typename... Params>
 	address_map_entry &w(device_finder<T, Reqd> &finder, Ret (U::*write)(Params...), const char *write_name)
-	{ const std::pair<device_t &, const char *> target(finder.finder_target()); device_t &device(*target.first.subdevice(target.second)); return w(emu::detail::make_delegate(write, write_name, device.tag(), make_pointer<U>(device))); }
+	{
+		const std::pair<device_t &, const char *> target(finder.finder_target());
+		device_t *device(target.first.subdevice(target.second));
+		assert(device != nullptr);
+		return w(emu::detail::make_delegate(write, write_name, device->tag(), make_pointer<U>(*device)));
+	}
 
 	template <typename T, bool Reqd, typename U, typename Ret, typename... Params>
 	address_map_entry &w(const device_finder<T, Reqd> &finder, Ret (U::*write)(Params...), const char *write_name)
-	{ const std::pair<device_t &, const char *> target(finder.finder_target()); device_t &device(*target.first.subdevice(target.second)); return w(emu::detail::make_delegate(write, write_name, device.tag(), make_pointer<U>(device))); }
+	{
+		const std::pair<device_t &, const char *> target(finder.finder_target());
+		device_t *device(target.first.subdevice(target.second));
+		assert(device != nullptr);
+		return w(emu::detail::make_delegate(write, write_name, device->tag(), make_pointer<U>(*device)));
+	}
 
 	template <typename T, bool Reqd, typename U, typename RetR, typename... ParamsR, typename V, typename RetW, typename... ParamsW>
 	address_map_entry &rw(device_finder<T, Reqd> &finder, RetR (U::*read)(ParamsR...), const char *read_name, RetW (V::*write)(ParamsW...), const char *write_name)
-	{ const std::pair<device_t &, const char *> target(finder.finder_target()); device_t &device(*target.first.subdevice(target.second)); return r(emu::detail::make_delegate(read, read_name, device.tag(), make_pointer<U>(device))).w(emu::detail::make_delegate(write, write_name, device.tag(), make_pointer<V>(device))); }
+	{
+		const std::pair<device_t &, const char *> target(finder.finder_target());
+		device_t *device(target.first.subdevice(target.second));
+		assert(device != nullptr);
+		return r(emu::detail::make_delegate(read, read_name, device->tag(), make_pointer<U>(*device)))
+			.w(emu::detail::make_delegate(write, write_name, device->tag(), make_pointer<V>(*device)));
+	}
 
 	template <typename T, bool Reqd, typename U, typename RetR, typename... ParamsR, typename V, typename RetW, typename... ParamsW>
 	address_map_entry &rw(const device_finder<T, Reqd> &finder, RetR (U::*read)(ParamsR...), const char *read_name, RetW (V::*write)(ParamsW...), const char *write_name)
-	{ const std::pair<device_t &, const char *> target(finder.finder_target()); device_t &device(*target.first.subdevice(target.second)); return r(emu::detail::make_delegate(read, read_name, device.tag(), make_pointer<U>(device))).w(emu::detail::make_delegate(write, write_name, device.tag(), make_pointer<V>(device))); }
+	{
+		const std::pair<device_t &, const char *> target(finder.finder_target());
+		device_t *device(target.first.subdevice(target.second));
+		assert(device != nullptr);
+		return r(emu::detail::make_delegate(read, read_name, device->tag(), make_pointer<U>(*device)))
+			.w(emu::detail::make_delegate(write, write_name, device->tag(), make_pointer<V>(*device)));
+	}
 
 	template <typename T, bool Reqd, typename U, typename Ret, typename... Params>
 	address_map_entry &m(device_finder<T, Reqd> &finder, Ret (U::*map)(Params...), const char *map_name)
-	{ const std::pair<device_t &, const char *> target(finder.finder_target()); device_t &device(*target.first.subdevice(target.second)); return m(&device, make_delegate(map, map_name, make_pointer<U>(device))); }
+	{
+		const std::pair<device_t &, const char *> target(finder.finder_target());
+		device_t *device(target.first.subdevice(target.second));
+		assert(device != nullptr);
+		return m(device, make_delegate(map, map_name, make_pointer<U>(*device)));
+	}
 
 	template <typename T, bool Reqd, typename U, typename Ret, typename... Params>
 	address_map_entry &m(const device_finder<T, Reqd> &finder, Ret (U::*map)(Params...), const char *map_name)
-	{ const std::pair<device_t &, const char *> target(finder.finder_target()); device_t &device(*target.first.subdevice(target.second)); return m(make_delegate(map, map_name, make_pointer<U>(device))); }
+	{
+		const std::pair<device_t &, const char *> target(finder.finder_target());
+		device_t *device(target.first.subdevice(target.second));
+		assert(device != nullptr);
+		return m(make_delegate(map, map_name, make_pointer<U>(*device)));
+	}
 
 
 	// lambda -> delegate converter