diff --git a/src/cw/mbag.h b/src/cw/mbag.h
index 534911a3..085edf67 100644
--- a/src/cw/mbag.h
+++ b/src/cw/mbag.h
@@ -58,6 +58,9 @@ struct mbag_typedef{
 	/** Cereate an item of this type from a string, which was previously
 	    created by the #del function. */
 	struct mbag_item * (*from_str)(const char *src);
+	/** A method to put this object to a buffer */
+	int (*put)(void *,uint8_t*dst);
+
 };
 
 /** The type for an mbag typedef */