diff --git a/ArcFormats/BitStream.cs b/ArcFormats/BitStream.cs
index 28d4b7e0..7fc6d5d0 100644
--- a/ArcFormats/BitStream.cs
+++ b/ArcFormats/BitStream.cs
@@ -37,7 +37,8 @@ namespace GameRes.Formats
         protected int       m_bits = 0;
         protected int       m_cached_bits = 0;
 
-        public Stream Input { get { return m_input; } }
+        public Stream  Input { get { return m_input; } }
+        public int CacheSize { get { return m_cached_bits; } }
 
         protected BitStream (Stream file, bool leave_open)
         {