diff --git a/c_micasad/lss/CASACrypto.cs b/c_micasad/lss/CASACrypto.cs
index 59f703c7..2c47dd41 100644
--- a/c_micasad/lss/CASACrypto.cs
+++ b/c_micasad/lss/CASACrypto.cs
@@ -241,8 +241,8 @@ namespace sscs.crypto
                         fsDecrypt.Close();                        
                         return null;
 		}
-                ulong fileLen = fsDecrypt.Length - HASH_SIZE;
-                byte[] fromEncrypt = new byte[fileLen];
+		ulong fileLen = (ulong)(fsDecrypt.Length - HASH_SIZE);
+		byte[] fromEncrypt = new byte[fileLen];
 
                 //Read the data out of the crypto stream.
                 int bytesRead = csDecrypt.Read(fromEncrypt, 0, fromEncrypt.Length);