diff --git a/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/SxROM.cs b/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/SxROM.cs
index e810325f35..4b25ceec8a 100644
--- a/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/SxROM.cs
+++ b/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/SxROM.cs
@@ -366,6 +366,9 @@ namespace BizHawk.Emulation.Cores.Nintendo.NES
 				case "HVC-SKROM": //ad&d dragons of flame (J)
 					AssertPrg(128, 256); AssertChr(128); AssertVram(0); AssertWram(8);
 					break;
+				case "NES-SKEPROM": // chip n dale 2 (proto)
+					AssertPrg(128, 256); AssertChr(128); AssertVram(0); AssertWram(0, 8);
+					break;
 				case "NES-SLROM": //castlevania 2
 				case "KONAMI-SLROM": //bayou billy
 				case "HVC-SLROM": //Adventures of Lolo 2 (J)