diff --git a/desmume/src/MMU.c b/desmume/src/MMU.c
index d36472e31..8a5fabf7f 100644
--- a/desmume/src/MMU.c
+++ b/desmume/src/MMU.c
@@ -1171,6 +1171,12 @@ void FASTCALL MMU_write16(u32 proc, u32 adr, u16 val)
 			case REG_DISPB_BLDALPHA:
 				GPU_setBLDALPHA(SubScreen.gpu,val) ;
 				break ;
+			case REG_DISPA_BLDY:
+				GPU_setBLDY(MainScreen.gpu,val) ;
+				break ;
+			case REG_DISPB_BLDY:
+				GPU_setBLDY(SubScreen.gpu,val) ;
+				break ;
 			case REG_IME :
 				MMU.reg_IME[proc] = val&1;
 				T1WriteWord(MMU.MMU_MEM[proc][0x40], 0x208, val);