diff --git a/src/BizHawk.Client.Common/RomLoader.cs b/src/BizHawk.Client.Common/RomLoader.cs
index 7f75937902..eaf8a3e280 100644
--- a/src/BizHawk.Client.Common/RomLoader.cs
+++ b/src/BizHawk.Client.Common/RomLoader.cs
@@ -202,7 +202,7 @@ namespace BizHawk.Client.Common
 		private List<Disc> DiscsFromXml(XmlGame xmlGame, string systemId, DiscType diskType)
 		{
 			var discs = new List<Disc>();
-			foreach (var e in xmlGame.AssetFullPaths.Where(a => IsDisc(Path.GetExtension(a))))
+			foreach (var e in xmlGame.AssetFullPaths.Where(a => Disc.IsValidExtension(Path.GetExtension(a))))
 			{
 				var disc = diskType.Create(e, str => { DoLoadErrorCallback(str, systemId, LoadErrorType.DiscError); });
 				if (disc != null)
@@ -417,7 +417,7 @@ namespace BizHawk.Client.Common
 						System = "PSX"
 					};
 				}
-				else if (IsDisc(ext))
+				else if (Disc.IsValidExtension(ext))
 				{
 					if (file.IsArchive)
 					{
@@ -768,7 +768,8 @@ namespace BizHawk.Client.Common
 								break;
 							case "GEN":
 								var genDiscs = DiscsFromXml(xmlGame, "GEN", DiscType.MegaCD);
-								var romBytes = xmlGame.Assets.Where(a => !IsDisc(a.Key))
+								var romBytes = xmlGame.Assets
+									.Where(a => !Disc.IsValidExtension(a.Key))
 									.Select(a => a.Value)
 									.FirstOrDefault();
 								if (!genDiscs.Any() && romBytes == null)
@@ -1107,11 +1108,5 @@ namespace BizHawk.Client.Common
 			Game = game;
 			return true;
 		}
-
-		private static bool IsDisc(string extension) =>
-			extension == ".iso"
-			|| extension == ".cue"
-			|| extension == ".ccd"
-			|| extension == ".mds";
 	}
 }
diff --git a/src/BizHawk.Emulation.DiscSystem/Disc.cs b/src/BizHawk.Emulation.DiscSystem/Disc.cs
index ecbbb9e1cf..d7af67ddf8 100644
--- a/src/BizHawk.Emulation.DiscSystem/Disc.cs
+++ b/src/BizHawk.Emulation.DiscSystem/Disc.cs
@@ -129,5 +129,10 @@ namespace BizHawk.Emulation.DiscSystem
 		internal Disc()
 		{}
 
+		public static bool IsValidExtension(string extension) =>
+			extension == ".iso"
+			|| extension == ".cue"
+			|| extension == ".ccd"
+			|| extension == ".mds";
 	}
 }
\ No newline at end of file
diff --git a/src/BizHawk.Emulation.DiscSystem/DiscExtensions.cs b/src/BizHawk.Emulation.DiscSystem/DiscExtensions.cs
index 41996ea073..b6a48b3789 100644
--- a/src/BizHawk.Emulation.DiscSystem/DiscExtensions.cs
+++ b/src/BizHawk.Emulation.DiscSystem/DiscExtensions.cs
@@ -4,15 +4,15 @@ namespace BizHawk.Emulation.DiscSystem
 {
 	public static class DiscExtensions
 	{
-		public static Disc Create(this DiscType diskType, string discPath, Action<string> errorCallback)
+		public static Disc Create(this DiscType type, string path, Action<string> errorCallback)
 		{
 			//--- load the disc in a context which will let us abort if it's going to take too long
-			var discMountJob = new DiscMountJob { IN_FromPath = discPath, IN_SlowLoadAbortThreshold = 8 };
+			var discMountJob = new DiscMountJob { IN_FromPath = path, IN_SlowLoadAbortThreshold = 8 };
 			discMountJob.Run();
 			var disc = discMountJob.OUT_Disc;
 			if (disc == null)
 			{
-				throw new InvalidOperationException($"Can't find the file specified: {discPath}");
+				throw new InvalidOperationException($"Can't find the file specified: {path}");
 			}
 
 			if (discMountJob.OUT_SlowLoadAborted)
@@ -28,9 +28,9 @@ namespace BizHawk.Emulation.DiscSystem
 
 			var discType = new DiscIdentifier(disc).DetectDiscType();
 
-			if (discType != diskType)
+			if (discType != type)
 			{
-				errorCallback($"Not a {diskType} disc");
+				errorCallback($"Not a {type} disc");
 				return null;
 			}