diff --git a/src/mame/drivers/vaportra.cpp b/src/mame/drivers/vaportra.cpp
index 9ae7938ecab..cd40a37db5e 100644
--- a/src/mame/drivers/vaportra.cpp
+++ b/src/mame/drivers/vaportra.cpp
@@ -233,7 +233,7 @@ MACHINE_CONFIG_START(vaportra_state::vaportra)
 
 	MCFG_GFXDECODE_ADD("gfxdecode", "palette", vaportra)
 	MCFG_PALETTE_ADD("palette", 1280)
-
+	MCFG_PALETTE_FORMAT(xxxxRRRRGGGGBBBB)
 
 	MCFG_DEVICE_ADD("tilegen1", DECO16IC, 0)
 	MCFG_DECO16IC_SPLIT(0)