diff --git a/client-libs/kaitai-struct-files/files/alpha__operation__bls_mode_unsigned.ksy b/client-libs/kaitai-struct-files/files/alpha__operation__bls_mode_unsigned.ksy
index 4a55505657938d0b1c284864c430662df49fab41..454865ebe155d84c3985c064965a72907a75400c 100644
--- a/client-libs/kaitai-struct-files/files/alpha__operation__bls_mode_unsigned.ksy
+++ b/client-libs/kaitai-struct-files/files/alpha__operation__bls_mode_unsigned.ksy
@@ -358,12 +358,6 @@ types:
       type: s4be
     - id: block_payload_hash
       size: 32
-    - id: dal_tag
-      type: u1
-      enum: bool
-    - id: dal
-      type: z
-      if: (dal_tag == bool::true)
   bls_mode_preattestation:
     seq:
     - id: level
diff --git a/src/proto_alpha/lib_protocol/operation_repr.ml b/src/proto_alpha/lib_protocol/operation_repr.ml
index 0fb269978f8c6358fcfc310f1c46acbd2a651286..bff7fd97cd65f2267a6afdf4e9eef2b3dba16ce2 100644
--- a/src/proto_alpha/lib_protocol/operation_repr.ml
+++ b/src/proto_alpha/lib_protocol/operation_repr.ml
@@ -1868,30 +1868,23 @@ module Encoding = struct
         {
           tag = 41;
           name = "bls_mode_attestation";
-          encoding =
-            merge_objs
-              consensus_aggregate_content_encoding
-              (obj1 (opt "dal" dal_content_encoding));
+          encoding = consensus_aggregate_content_encoding;
           select =
             (function Contents (Attestation _ as op) -> Some op | _ -> None);
           proj =
-            (fun (Attestation {consensus_content; dal_content}) ->
-              ( {
-                  level = consensus_content.level;
-                  round = consensus_content.round;
-                  block_payload_hash = consensus_content.block_payload_hash;
-                },
-                Option.map
-                  (fun dal_content -> dal_content.attestation)
-                  dal_content ));
+            (fun (Attestation {consensus_content; dal_content = _}) ->
+              {
+                level = consensus_content.level;
+                round = consensus_content.round;
+                block_payload_hash = consensus_content.block_payload_hash;
+              });
           inj =
-            (fun ({level; round; block_payload_hash}, dal_content) ->
+            (fun {level; round; block_payload_hash} ->
               Attestation
                 {
                   consensus_content =
                     {slot = Slot_repr.zero; level; round; block_payload_hash};
-                  dal_content =
-                    Option.map (fun attestation -> {attestation}) dal_content;
+                  dal_content = None;
                 });
         }
 
diff --git a/tezt/tests/expected/encoding.ml/Alpha- protocol encoding regression test- operation.bls_mode_unsigned.out b/tezt/tests/expected/encoding.ml/Alpha- protocol encoding regression test- operation.bls_mode_unsigned.out
index c96d8207fd52bcd478c0507608246ede31f82207..6728d233e47dfff9134fcf8c513c668e2d81d338 100644
--- a/tezt/tests/expected/encoding.ml/Alpha- protocol encoding regression test- operation.bls_mode_unsigned.out	
+++ b/tezt/tests/expected/encoding.ml/Alpha- protocol encoding regression test- operation.bls_mode_unsigned.out	
@@ -10,9 +10,9 @@
     }
   ]
 }'
-0e5751c026e543b2e8ab2eb06099daa1d1e5df47778f7787faab45cdf12fe3a8290000053300000000000000000000000000000000000000000000000000000000000000000000000000
+0e5751c026e543b2e8ab2eb06099daa1d1e5df47778f7787faab45cdf12fe3a82900000533000000000000000000000000000000000000000000000000000000000000000000000000
 
-./octez-codec decode alpha.operation.bls_mode_unsigned from 0e5751c026e543b2e8ab2eb06099daa1d1e5df47778f7787faab45cdf12fe3a8290000053300000000000000000000000000000000000000000000000000000000000000000000000000
+./octez-codec decode alpha.operation.bls_mode_unsigned from 0e5751c026e543b2e8ab2eb06099daa1d1e5df47778f7787faab45cdf12fe3a82900000533000000000000000000000000000000000000000000000000000000000000000000000000
 { "branch": "BKpbfCvh777DQHnXjU2sqHvVUNZ7dBAdqEfKkdw8EGSkD9LSYXb",
   "contents":
     [ { "kind": "bls_mode_attestation", "level": 1331, "round": 0,