diff --git a/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/Mapper091.cs b/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/Mapper091.cs
index dca774e1be..8a882247be 100644
--- a/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/Mapper091.cs
+++ b/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/Mapper091.cs
@@ -37,7 +37,9 @@ namespace BizHawk.Emulation.Cores.Nintendo.NES
 			prg_regs_8k[2] = 0xFE;
 			
 			mmc3 = new MMC3(this, 0x7FFFFFFF);
-			
+
+			SetMirrorType(Cart.pad_h, Cart.pad_v);
+
 			return true;
 		}