diff --git a/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj b/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
index 5fb0c7bd6e..356d3b37ea 100644
--- a/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
+++ b/BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj
@@ -720,6 +720,7 @@
     </Compile>
     <Compile Include="Consoles\Nintendo\GBA\VBARegisterHelper.cs" />
     <Compile Include="Consoles\Nintendo\GBHawk\Audio.cs" />
+    <Compile Include="Consoles\Nintendo\GBHawk\Mappers\Mapper_WisdomTree.cs" />
     <Compile Include="Consoles\Nintendo\GBHawk\Mappers\Mapper_RockMan8.cs" />
     <Compile Include="Consoles\Nintendo\GBHawk\Mappers\Mapper_Sachen_MMC2.cs" />
     <Compile Include="Consoles\Nintendo\GBHawk\Mappers\Mapper_Sachen_MMC1.cs" />
diff --git a/BizHawk.Emulation.Cores/Consoles/Nintendo/GBHawk/GBC_PPU.cs b/BizHawk.Emulation.Cores/Consoles/Nintendo/GBHawk/GBC_PPU.cs
index 7b70954462..6b55e46485 100644
--- a/BizHawk.Emulation.Cores/Consoles/Nintendo/GBHawk/GBC_PPU.cs
+++ b/BizHawk.Emulation.Cores/Consoles/Nintendo/GBHawk/GBC_PPU.cs
@@ -109,6 +109,8 @@ namespace BizHawk.Emulation.Cores.Nintendo.GBHawk
 					}
 
 					LCDC = value;
+
+					Console.WriteLine(value);
 					break; 
 				case 0xFF41: // STAT
 					// writing to STAT during mode 0 or 2 causes a STAT IRQ
@@ -363,6 +365,8 @@ namespace BizHawk.Emulation.Cores.Nintendo.GBHawk
 						LY_inc = 1;
 						Core.in_vblank = false;
 
+						STAT &= 0xFC;
+
 						// special note here, the y coordiate of the window is kept if the window is deactivated
 						// meaning it will pick up where it left off if re-enabled later
 						// so we don't reset it in the scanline loop
@@ -431,6 +435,11 @@ namespace BizHawk.Emulation.Cores.Nintendo.GBHawk
 						Core.REG_FF0F |= 0x01;
 					}
 
+					if ((cycle == 84) && (LY == 144))
+					{
+						if (STAT.Bit(5)) { VBL_INT = false; }
+					}
+					
 					if ((LY == 153) && (cycle == 6))
 					{
 						LY = 0;
@@ -521,7 +530,6 @@ namespace BizHawk.Emulation.Cores.Nintendo.GBHawk
 						}
 						else if ((cycle >= 80) && (LY < 144))
 						{
-
 							if (cycle == 84)
 							{
 								STAT &= 0xFC;
@@ -613,8 +621,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.GBHawk
 		}
 
 		public override void render(int render_cycle)
-		{
-		
+		{	
 			// we are now in STAT mode 3
 			// NOTE: presumably the first necessary sprite is fetched at sprite evaulation
 			// i.e. just keeping track of the lowest x-value sprite
@@ -768,7 +775,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.GBHawk
 								}
 
 								// There is another priority bit in GBC, that can still override sprite priority
-								if (LCDC.Bit(0) && tile_data_latch[2].Bit(7) && Core.GBC_compat)
+								if (LCDC.Bit(0) && tile_data_latch[2].Bit(7) && (ref_pixel != 0) && Core.GBC_compat)
 								{
 									use_sprite = false;
 								}
diff --git a/BizHawk.Emulation.Cores/Consoles/Nintendo/GBHawk/GB_PPU.cs b/BizHawk.Emulation.Cores/Consoles/Nintendo/GBHawk/GB_PPU.cs
index 1cae78cc21..5a14dad97f 100644
--- a/BizHawk.Emulation.Cores/Consoles/Nintendo/GBHawk/GB_PPU.cs
+++ b/BizHawk.Emulation.Cores/Consoles/Nintendo/GBHawk/GB_PPU.cs
@@ -128,7 +128,6 @@ namespace BizHawk.Emulation.Cores.Nintendo.GBHawk
 					}
 
 					cycle = 0;
-
 					LY += LY_inc;
 					Core.cpu.LY = LY;
 
@@ -209,6 +208,11 @@ namespace BizHawk.Emulation.Cores.Nintendo.GBHawk
 						Core.REG_FF0F |= 0x01;
 					}
 
+					if ((cycle == 84) && (LY == 144))
+					{
+						if (STAT.Bit(5)) { VBL_INT = false; }
+					}
+
 					if ((LY == 153) && (cycle == 6))
 					{
 						LY = 0;
@@ -243,7 +247,6 @@ namespace BizHawk.Emulation.Cores.Nintendo.GBHawk
 
 						if (cycle == 84)
 						{
-
 							STAT &= 0xFC;
 							STAT |= 0x03;
 							OAM_INT = false;
@@ -340,7 +343,6 @@ namespace BizHawk.Emulation.Cores.Nintendo.GBHawk
 						LYC_INT = false;
 						STAT &= 0xFB;
 					}
-
 				}
 				else if ((cycle == 4) && (LY != 0))
 				{
@@ -419,7 +421,6 @@ namespace BizHawk.Emulation.Cores.Nintendo.GBHawk
 				first_fetch = true;
 				no_sprites = false;
 				evaled_sprites = 0;
-
 				window_pre_render = false;
 				window_latch = LCDC.Bit(5);
 
diff --git a/BizHawk.Emulation.Cores/Consoles/Nintendo/GBHawk/Mappers/Mapper_MBC5.cs b/BizHawk.Emulation.Cores/Consoles/Nintendo/GBHawk/Mappers/Mapper_MBC5.cs
index 3c1ea0c60f..cbaf5bc601 100644
--- a/BizHawk.Emulation.Cores/Consoles/Nintendo/GBHawk/Mappers/Mapper_MBC5.cs
+++ b/BizHawk.Emulation.Cores/Consoles/Nintendo/GBHawk/Mappers/Mapper_MBC5.cs
@@ -22,6 +22,7 @@ namespace BizHawk.Emulation.Cores.Nintendo.GBHawk
 
 			// some games have sizes that result in a degenerate ROM, account for it here
 			if (ROM_mask > 4) { ROM_mask |= 3; }
+			if (ROM_mask > 0x100) { ROM_mask |= 0xFF; }
 
 			RAM_mask = 0;
 			if (Core.cart_RAM != null)