diff --git a/BizHawk.Emulation.Cores/Consoles/Sega/gpgx/GPGX.cs b/BizHawk.Emulation.Cores/Consoles/Sega/gpgx/GPGX.cs
index a9c266888a..c31cb97e03 100644
--- a/BizHawk.Emulation.Cores/Consoles/Sega/gpgx/GPGX.cs
+++ b/BizHawk.Emulation.Cores/Consoles/Sega/gpgx/GPGX.cs
@@ -317,6 +317,7 @@ namespace BizHawk.Emulation.Cores.Consoles.Sega.gpgx
 				if (AttachedCore != this)
 					throw new Exception();
 				AttachedCore = null;
+				disposed = true;
 			}
 		}