diff --git a/nest/attrs.h b/nest/attrs.h
index 3a4b0acd..d88a73f3 100644
--- a/nest/attrs.h
+++ b/nest/attrs.h
@@ -111,7 +111,7 @@ static inline struct adata *
 aggregator_to_old(struct linpool *pool, const struct adata *a)
 {
   struct adata *d = lp_alloc_adata(pool, 8);
-  put_u32(d->data, 0xFFFF);
+  put_u32(d->data, AS_TRANS);
   memcpy(d->data + 4, a->data + 4, 4);
   return d;
 }
diff --git a/proto/bgp/attrs.c b/proto/bgp/attrs.c
index 39297dd7..655ddb62 100644
--- a/proto/bgp/attrs.c
+++ b/proto/bgp/attrs.c
@@ -577,6 +577,7 @@ bgp_encode_aggregator(struct bgp_write_state *s, eattr *a, byte *buf, uint size)
     /* Prepare 16-bit AGGREGATOR (from 32-bit one) in a temporary buffer */
     byte *dst = alloca(6);
     len = aggregator_32to16(dst, data);
+    data = dst;
   }
 
   return bgp_put_attr(buf, size, BA_AGGREGATOR, a->flags, data, len);