diff --git a/proto/bgp/attrs.c b/proto/bgp/attrs.c
index 6752cb7f..24ba00ba 100644
--- a/proto/bgp/attrs.c
+++ b/proto/bgp/attrs.c
@@ -88,7 +88,7 @@ bgp_set_attr(ea_list **attrs, struct linpool *pool, uint code, uint flags, uintp
       attrs,
       pool,
       EA_CODE(PROTOCOL_BGP, code),
-      flags,
+      flags & ~BAF_EXT_LEN,
       bgp_attr_table[code].type,
       val
   );
@@ -118,7 +118,7 @@ bgp_set_attr(ea_list **attrs, struct linpool *pool, uint code, uint flags, uintp
 static inline int
 bgp_put_attr_hdr3(byte *buf, uint code, uint flags, uint len)
 {
-  *buf++ = flags;
+  *buf++ = flags & ~BAF_EXT_LEN;
   *buf++ = code;
   *buf++ = len;
   return 3;