diff --git a/ArcFormats/Will/ArcWILL.cs b/ArcFormats/Will/ArcWILL.cs
index 3398eaef..e3dac968 100644
--- a/ArcFormats/Will/ArcWILL.cs
+++ b/ArcFormats/Will/ArcWILL.cs
@@ -57,6 +57,7 @@ namespace GameRes.Formats.Will
         ArcOpener ()
         {
             Extensions = new string[] { "arc" };
+            Signatures = new uint[] { 1, 0 };
         }
 
         public override ArcFile TryOpen (ArcView file)