diff --git a/src/emu/video/psx.c b/src/emu/video/psx.c
index c6152682ead..54b81137941 100644
--- a/src/emu/video/psx.c
+++ b/src/emu/video/psx.c
@@ -3800,7 +3800,7 @@ PALETTE_INIT_MEMBER( psxgpu_device, psx )
 MACHINE_CONFIG_FRAGMENT( psxgpu )
 	MCFG_SCREEN_ADD("screen", RASTER)
 	MCFG_SCREEN_REFRESH_RATE( 60 )
-	MCFG_SCREEN_VBLANK_TIME(ATTOSECONDS_IN_USEC( 0 ))
+	MCFG_SCREEN_VBLANK_TIME(ATTOSECONDS_IN_USEC(2500) /* not accurate */)
 	MCFG_SCREEN_SIZE( 1024, 1024 )
 	MCFG_SCREEN_VISIBLE_AREA( 0, 639, 0, 479 )
 	MCFG_SCREEN_UPDATE_DEVICE( DEVICE_SELF, psxgpu_device, update_screen )