diff --git a/xbin.py b/xbin.py
index a061262..38ea600 100644
--- a/xbin.py
+++ b/xbin.py
@@ -323,8 +323,9 @@ def WriteMetaVec4Block(file, _hash, vec):
 
     @staticmethod
     def WriteCommentBlock(file, comment):
-        comment = bytearray(comment.encode('utf-8'))
-        data = struct.pack('Hxx%ds' % (len(comment) + 1), 0xC355, comment)
+        comment = __str_packable__(comment)
+        padded_size = padded(len(comment) + 1)
+        data = struct.pack('Hxx%ds' % padded_size, 0xC355, comment)
         file.write(data)
 
     @staticmethod