diff --git a/CHANGES.rst b/CHANGES.rst
index 757e3f1615f1b9095f01f139b8c2b35d5abf0395..8d202a0ad8bd9498cf0d9bfa0007b8b9d49ec7ef 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -236,6 +236,9 @@ DAL node
 - **Breaking change** The baker daemon ``--dal-node-timeout-percentage``
   argument has been removed. (MR :gl:`!15554`)
 
+- A warning is emitted when registering a public key hash (as an attester
+  profile) that does not correspond to that of a delegate. (MR :gl:`!16336`)
+
 Protocol
 ~~~~~~~~
 
diff --git a/src/bin_dal_node/RPC_server.ml b/src/bin_dal_node/RPC_server.ml
index 523334ddd018e5745649fd89031af88e09382918..ed5ba21bce827f3613c386b97e12676b0d6e4346 100644
--- a/src/bin_dal_node/RPC_server.ml
+++ b/src/bin_dal_node/RPC_server.ml
@@ -270,6 +270,10 @@ module Profile_handlers = struct
     let open Lwt_result_syntax in
     let gs_worker = Node_context.get_gs_worker ctxt in
     call_handler1 (fun () ->
+        let* () =
+          Node_context.warn_if_attesters_not_delegates ctxt operator_profiles
+          |> lwt_map_error (fun e -> `Other e)
+        in
         let proto_parameters = Node_context.get_proto_parameters ctxt in
         match
           Profile_manager.add_and_register_operator_profile
diff --git a/src/bin_dal_node/daemon.ml b/src/bin_dal_node/daemon.ml
index 9d21b270c8de9f619d7ac43de87873f816fd75be..9d79b1274169f2240cb9446c525e871796e7ae5f 100644
--- a/src/bin_dal_node/daemon.ml
+++ b/src/bin_dal_node/daemon.ml
@@ -1374,6 +1374,15 @@ let run ~data_dir ~configuration_override =
       transport_layer
       cctxt
   in
+  let* () =
+    match Profile_manager.get_profiles profile_ctxt with
+    | Operator profile ->
+        Node_context.warn_if_attesters_not_delegates
+          ctxt
+          ~level:head_level
+          profile
+    | _ -> return_unit
+  in
   Gossipsub.Worker.Validate_message_hook.set
     (Handler.gossipsub_app_messages_validation
        ctxt
diff --git a/src/bin_dal_node/event.ml b/src/bin_dal_node/event.ml
index 3f25a693b768dc78f6da4825fee5a75409edae67..5b427ba74991c4660418800aab4e109f33d18d1b 100644
--- a/src/bin_dal_node/event.ml
+++ b/src/bin_dal_node/event.ml
@@ -800,3 +800,13 @@ let trap_delegate_attestation_not_found =
     ("shard_index", Data_encoding.int31)
     ("published_level", Data_encoding.int32)
     ("attested_level", Data_encoding.int32)
+
+let registered_pkh_not_a_delegate =
+  declare_1
+    ~section
+    ~name:"register_pkh_not_a_delegate"
+    ~msg:
+      "The public key hash {pkh} registered by PATCH /profiles is not a \
+       delegate."
+    ~level:Warning
+    ("pkh", Signature.Public_key_hash.encoding)
diff --git a/src/bin_dal_node/node_context.ml b/src/bin_dal_node/node_context.ml
index 037b6dfa776fb022f939625851bcda699f7b36c7..3447e0f97d9d487ba2d8084dcd76f33834b9a4d2 100644
--- a/src/bin_dal_node/node_context.ml
+++ b/src/bin_dal_node/node_context.ml
@@ -202,6 +202,35 @@ let version {config; _} =
   let network_name = config.Configuration_file.network_name in
   Types.Version.make ~network_version:(Gossipsub.version ~network_name)
 
+(* TODO: https://gitlab.com/tezos/tezos/-/issues/7706
+   This level argument would not be needed if we had the head level in the context. *)
+let warn_if_attesters_not_delegates ctxt ?level operator_profiles =
+  let open Lwt_result_syntax in
+  let pkh_set = Operator_profile.attesters operator_profiles in
+  if Signature.Public_key_hash.Set.is_empty pkh_set then return_unit
+  else
+    let* level_opt =
+      match level with
+      | Some _ -> return level
+      | None ->
+          let store = get_store ctxt in
+          let lpl_store = Store.last_processed_level store in
+          Store.Last_processed_level.load lpl_store
+    in
+    Option.iter_es
+      (fun level ->
+        let cctxt = get_tezos_node_cctxt ctxt in
+        let*? (module Plugin) = get_plugin_for_level ctxt ~level in
+        Signature.Public_key_hash.Set.iter_es
+          (fun pkh ->
+            let* is_delegate = Plugin.is_delegate cctxt ~pkh in
+            if not is_delegate then
+              let*! () = Event.(emit registered_pkh_not_a_delegate pkh) in
+              return_unit
+            else return_unit)
+          pkh_set)
+      level_opt
+
 module P2P = struct
   let connect {transport_layer; _} ?timeout point =
     Gossipsub.Transport_layer.connect transport_layer ?timeout point
diff --git a/src/bin_dal_node/node_context.mli b/src/bin_dal_node/node_context.mli
index 628bb67694ce005127bfb93409dd5ba5acd3400c..34b83a9955c4a7e1aea0e98fadc77e991c5f1db8 100644
--- a/src/bin_dal_node/node_context.mli
+++ b/src/bin_dal_node/node_context.mli
@@ -168,6 +168,13 @@ val fetch_committee :
 (** [version ctxt] returns the current version of the node *)
 val version : t -> Types.Version.t
 
+(** Emit a warning for each public key hash in the given operator profile (if
+    any) that is not that of a L1-registered delegate. The optional [level]
+    argument is used to specify for which level to obtain the plugin; if not
+    given the last process level is used (if found in the store). *)
+val warn_if_attesters_not_delegates :
+  t -> ?level:int32 -> Operator_profile.t -> unit tzresult Lwt.t
+
 (** Module for P2P-related accessors.  *)
 module P2P : sig
   (** [connect t ?timeout point] initiates a connection to the point
diff --git a/src/lib_dal_node/dal_plugin.ml b/src/lib_dal_node/dal_plugin.ml
index 50abdc0a4e252189d9fe6bd7550ed1b33ce03df4..0a1ed7a0bf254657fe6adeb4f4700cc51764cf38 100644
--- a/src/lib_dal_node/dal_plugin.ml
+++ b/src/lib_dal_node/dal_plugin.ml
@@ -176,6 +176,11 @@ module type T = sig
     proof:Cryptobox.shard_proof ->
     unit tzresult Lwt.t
 
+  val is_delegate :
+    Tezos_rpc.Context.generic ->
+    pkh:Signature.Public_key_hash.t ->
+    bool tzresult Lwt.t
+
   (* Section of helpers for Skip lists *)
 
   module Skip_list : sig
diff --git a/src/lib_dal_node/dal_plugin.mli b/src/lib_dal_node/dal_plugin.mli
index ab66a17f5e991a8efe7a11967566b0b7224d68ce..1e5fcb255e8cd81fcf5acdd221bb30a5e7b1e621 100644
--- a/src/lib_dal_node/dal_plugin.mli
+++ b/src/lib_dal_node/dal_plugin.mli
@@ -139,6 +139,11 @@ module type T = sig
     proof:Cryptobox.shard_proof ->
     unit tzresult Lwt.t
 
+  val is_delegate :
+    Tezos_rpc.Context.generic ->
+    pkh:Signature.Public_key_hash.t ->
+    bool tzresult Lwt.t
+
   (* Section of helpers for Skip lists *)
 
   module Skip_list : sig
diff --git a/src/proto_020_PsParisC/lib_dal/dal_plugin_registration.ml b/src/proto_020_PsParisC/lib_dal/dal_plugin_registration.ml
index bb9902374da088cb5bf9c1244f1393f56de1d657..03fbc81402eede4e48ae05dad9cd859817417891 100644
--- a/src/proto_020_PsParisC/lib_dal/dal_plugin_registration.ml
+++ b/src/proto_020_PsParisC/lib_dal/dal_plugin_registration.ml
@@ -204,6 +204,9 @@ module Plugin = struct
   let is_attested attestation slot_index =
     match Bitset.mem attestation slot_index with Ok b -> b | Error _ -> false
 
+  let is_delegate _ctxt ~pkh:_ =
+    failwith "Plugin.ParisC.is_delegate is not available"
+
   (* Section of helpers for Skip lists *)
 
   module Skip_list = struct
diff --git a/src/proto_021_PsQuebec/lib_dal/dal_plugin_registration.ml b/src/proto_021_PsQuebec/lib_dal/dal_plugin_registration.ml
index bb6943c11d37c9ee8355ded55e6394748c47d9e2..00fe7bcfed3425e21c0ca8dc66d4313e26ec50ae 100644
--- a/src/proto_021_PsQuebec/lib_dal/dal_plugin_registration.ml
+++ b/src/proto_021_PsQuebec/lib_dal/dal_plugin_registration.ml
@@ -204,6 +204,17 @@ module Plugin = struct
   let is_attested attestation slot_index =
     match Bitset.mem attestation slot_index with Ok b -> b | Error _ -> false
 
+  let is_delegate ctxt ~pkh =
+    let open Lwt_result_syntax in
+    let cpctxt = new Protocol_client_context.wrap_rpc_context ctxt in
+    (* We just want to know whether <pkh> is a delegate. We call
+       'context/delegates/<pkh>/deactivated' just because it should be cheaper
+       than calling 'context/delegates/<pkh>/' (called [Delegate.info]). *)
+    let*! res =
+      Plugin.Alpha_services.Delegate.deactivated cpctxt (`Main, `Head 0) pkh
+    in
+    return @@ match res with Ok _deactivated -> true | Error _ -> false
+
   (* Section of helpers for Skip lists *)
 
   module Skip_list = struct
diff --git a/src/proto_alpha/lib_dal/dal_plugin_registration.ml b/src/proto_alpha/lib_dal/dal_plugin_registration.ml
index 52c418c72fcc553d252f18ea14400ee3529b9938..f132674c363ae1c9cec727774f026505ed2e62a2 100644
--- a/src/proto_alpha/lib_dal/dal_plugin_registration.ml
+++ b/src/proto_alpha/lib_dal/dal_plugin_registration.ml
@@ -245,6 +245,17 @@ module Plugin = struct
     | Ok b -> b
     | Error _ -> false
 
+  let is_delegate ctxt ~pkh =
+    let open Lwt_result_syntax in
+    let cpctxt = new Protocol_client_context.wrap_rpc_context ctxt in
+    (* We just want to know whether <pkh> is a delegate. We call
+       'context/delegates/<pkh>/deactivated' just because it should be cheaper
+       than calling 'context/delegates/<pkh>/' (called [Delegate.info]). *)
+    let*! res =
+      Plugin.Alpha_services.Delegate.deactivated cpctxt (`Main, `Head 0) pkh
+    in
+    return @@ match res with Ok _deactivated -> true | Error _ -> false
+
   (* Section of helpers for Skip lists *)
 
   module Skip_list = struct