diff --git a/DatSplit/DatSplit.cs b/DatSplit/DatSplit.cs
index 97a4c1ee..7858d652 100644
--- a/DatSplit/DatSplit.cs
+++ b/DatSplit/DatSplit.cs
@@ -68,9 +68,9 @@ namespace DatSplit
 
 			// Then write out both files
 			Output.WriteToDat(Path.GetFileNameWithoutExtension(_filename) + "." + _extA, Path.GetFileNameWithoutExtension(_filename) + "." + _extA,
-				"", "", "", "", false, Path.GetExtension(_filename) == ".dat", "", romsA, logger);
+				"", "", "", "", false, !RomManipulation.IsXmlDat(_filename), "", romsA, logger);
 			Output.WriteToDat(Path.GetFileNameWithoutExtension(_filename) + "." + _extB, Path.GetFileNameWithoutExtension(_filename) + "." + _extB,
-				"", "", "", "", false, Path.GetExtension(_filename) == ".dat", "", romsB, logger);
+				"", "", "", "", false, !RomManipulation.IsXmlDat(_filename), "", romsB, logger);
 
 			logger.Close();
 		}
diff --git a/SabreHelper/RomManipulation.cs b/SabreHelper/RomManipulation.cs
index 8934e02c..5c57a172 100644
--- a/SabreHelper/RomManipulation.cs
+++ b/SabreHelper/RomManipulation.cs
@@ -292,5 +292,19 @@ namespace SabreTools.Helper
 				return (norename ? String.Compare(x.Game, y.Game) : x.SystemID - y.SystemID);
 			});
 		}
+
+		public static bool IsXmlDat(string filename)
+		{
+			XmlDocument doc = new XmlDocument();
+			try
+			{
+				doc.LoadXml(File.ReadAllText(filename));
+			}
+			catch (XmlException)
+			{
+				return false;
+			}
+			return true;
+		}
 	}
 }
diff --git a/SingleGame/SingleGame.cs b/SingleGame/SingleGame.cs
index 5a5d5227..df399717 100644
--- a/SingleGame/SingleGame.cs
+++ b/SingleGame/SingleGame.cs
@@ -133,7 +133,7 @@ namespace SabreTools
 
 			// Now write the file out accordingly
 			Output.WriteToDat(Path.GetFileNameWithoutExtension(filename),
-				Path.GetFileNameWithoutExtension(filename), "", "", "", "", _forceunpack, Path.GetExtension(filename) == ".dat", Path.GetDirectoryName(filename), outroms, logger);
+				Path.GetFileNameWithoutExtension(filename), "", "", "", "", _forceunpack, !RomManipulation.IsXmlDat(filename), Path.GetDirectoryName(filename), outroms, logger);
 		}
 	}
 }