diff --git a/Assets/Cryville/Crtr/Extensions/Malody/MalodyChartConverter.cs b/Assets/Cryville/Crtr/Extensions/Malody/MalodyChartConverter.cs
index 1ccae69..c284cc3 100644
--- a/Assets/Cryville/Crtr/Extensions/Malody/MalodyChartConverter.cs
+++ b/Assets/Cryville/Crtr/Extensions/Malody/MalodyChartConverter.cs
@@ -18,6 +18,7 @@ namespace Cryville.Crtr.Extensions.Malody {
 		public override IEnumerable<Resource> ConvertFrom(FileInfo file) {
 			List<Resource> result = new List<Resource>();
 			MalodyChart src;
+			if (file.Extension != ".mc") throw new NotImplementedException("mcz file is not supported");
 			using (var reader = new StreamReader(file.FullName)) {
 				src = JsonConvert.DeserializeObject<MalodyChart>(reader.ReadToEnd());
 			}