diff --git a/src/mame/machine/atarigen.h b/src/mame/machine/atarigen.h
index c80110ef99f..69ca704078b 100644
--- a/src/mame/machine/atarigen.h
+++ b/src/mame/machine/atarigen.h
@@ -48,7 +48,7 @@
 	devcb = &atari_vad_device::static_set_scanline_int_cb(*device, DEVCB_##_intcb);
 
 #define MCFG_ATARI_VAD_PLAYFIELD(_class, _gfxtag, _getinfo) \
-	{ std::string fulltag(device->tag(), ":playfield"); device_t *device; \
+	{ std::string fulltag(device->tag()); fulltag.append(":playfield"); device_t *device; \
 	MCFG_TILEMAP_ADD(fulltag.c_str()) \
 	MCFG_TILEMAP_GFXDECODE("^" _gfxtag) \
 	MCFG_TILEMAP_BYTES_PER_ENTRY(2) \
@@ -57,7 +57,7 @@
 	MCFG_TILEMAP_LAYOUT_STANDARD(SCAN_COLS, 64,64) }
 
 #define MCFG_ATARI_VAD_PLAYFIELD2(_class, _gfxtag, _getinfo) \
-	{ std::string fulltag(device->tag(), ":playfield2"); device_t *device; \
+	{ std::string fulltag(device->tag()); fulltag.append(":playfield2"); device_t *device; \
 	MCFG_TILEMAP_ADD(fulltag.c_str()) \
 	MCFG_TILEMAP_GFXDECODE("^" _gfxtag) \
 	MCFG_TILEMAP_BYTES_PER_ENTRY(2) \
@@ -67,7 +67,7 @@
 	MCFG_TILEMAP_TRANSPARENT_PEN(0) }
 
 #define MCFG_ATARI_VAD_ALPHA(_class, _gfxtag, _getinfo) \
-	{ std::string fulltag(device->tag(), ":alpha"); device_t *device; \
+	{ std::string fulltag(device->tag()); fulltag.append(":alpha"); device_t *device; \
 	MCFG_TILEMAP_ADD(fulltag.c_str()) \
 	MCFG_TILEMAP_GFXDECODE("^" _gfxtag) \
 	MCFG_TILEMAP_BYTES_PER_ENTRY(2) \
@@ -77,7 +77,7 @@
 	MCFG_TILEMAP_TRANSPARENT_PEN(0) }
 
 #define MCFG_ATARI_VAD_MOB(_config, _gfxtag) \
-	{ std::string fulltag(device->tag(), ":mob"); device_t *device; \
+	{ std::string fulltag(device->tag()); fulltag.append(":mob"); device_t *device; \
 	MCFG_ATARI_MOTION_OBJECTS_ADD(fulltag.c_str(), "^^screen", _config) \
 	MCFG_ATARI_MOTION_OBJECTS_GFXDECODE("^" _gfxtag) }