diff --git a/include/mISDN/mbuffer.h b/include/mISDN/mbuffer.h
index 5e3dc96..8e6ed52 100644
--- a/include/mISDN/mbuffer.h
+++ b/include/mISDN/mbuffer.h
@@ -54,7 +54,7 @@ struct mbuffer {
 	struct l3_msg		l3;
 } __attribute__((__may_alias__));
 
-#define	MBUFFER_DATA_SIZE	280
+#define	MBUFFER_DATA_SIZE	400
 
 /*
  * init mbuffer caching