diff --git a/src/lib_shell/distributed_db.ml b/src/lib_shell/distributed_db.ml
index 1385ba664..67d3cd59c 100644
--- a/src/lib_shell/distributed_db.ml
+++ b/src/lib_shell/distributed_db.ml
@@ -31,6 +31,7 @@ module Make_raw
        Distributed_db_functors.MEMORY_TABLE with type key := Hash.t)
     (Request_message : sig
        type param
+       val max_length : int
        val forge : param -> Hash.t list -> Message.t
      end)
     (Precheck : Distributed_db_functors.PRECHECK
@@ -40,8 +41,10 @@ module Make_raw
   module Request = struct
     type param = Request_message.param request_param
     let active { active } = active ()
-    let send { data ; send } gid keys =
-      send gid (Request_message.forge data keys)
+    let rec send state gid keys =
+      let first_keys, keys = List.split_n Request_message.max_length keys in
+      state.send gid (Request_message.forge state.data first_keys) ;
+      if keys <> [] then send state gid keys
   end
 
   module Scheduler =
@@ -82,6 +85,7 @@ module Raw_operation =
     (Operation_hash.Table)
     (struct
       type param = unit
+      let max_length = 10
       let forge () keys = Message.Get_operations keys
     end)
     (struct
@@ -112,6 +116,7 @@ module Raw_block_header =
     (Block_hash.Table)
     (struct
       type param = unit
+      let max_length = 10
       let forge () keys = Message.Get_block_headers keys
     end)
     (struct
@@ -164,6 +169,7 @@ module Raw_operation_hashes = struct
       (Operations_table)
       (struct
         type param = unit
+        let max_length = 10
         let forge () keys =
           Message.Get_operation_hashes_for_blocks keys
       end)
@@ -232,6 +238,7 @@ module Raw_operations = struct
       (Operations_table)
       (struct
         type param = unit
+        let max_length = 10
         let forge () keys =
           Message.Get_operations_for_blocks keys
       end)
@@ -281,6 +288,7 @@ module Raw_protocol =
     (Protocol_hash.Table)
     (struct
       type param = unit
+      let max_length = 10
       let forge () keys = Message.Get_protocols keys
     end)
     (struct
diff --git a/src/lib_shell/distributed_db_message.ml b/src/lib_shell/distributed_db_message.ml
index 04bdc688b..e91bfec23 100644
--- a/src/lib_shell/distributed_db_message.ml
+++ b/src/lib_shell/distributed_db_message.ml
@@ -90,7 +90,7 @@ let encoding =
 
     case ~tag:0x20
       ~title:"Get_block_headers"
-      (obj1 (req "get_block_headers" (list Block_hash.encoding)))
+      (obj1 (req "get_block_headers" (list ~max_length:10 Block_hash.encoding)))
       (function
         | Get_block_headers bhs -> Some bhs
         | _ -> None)
@@ -106,7 +106,7 @@ let encoding =
 
     case ~tag:0x30
       ~title:"Get_operations"
-      (obj1 (req "get_operations" (list Operation_hash.encoding)))
+      (obj1 (req "get_operations" (list ~max_length:10 Operation_hash.encoding)))
       (function
         | Get_operations bhs -> Some bhs
         | _ -> None)
@@ -121,7 +121,7 @@ let encoding =
     case ~tag:0x40
       ~title:"Get_protocols"
       (obj1
-         (req "get_protocols" (list  Protocol_hash.encoding)))
+         (req "get_protocols" (list ~max_length:10 Protocol_hash.encoding)))
       (function
         | Get_protocols protos -> Some protos
         | _ -> None)
@@ -136,7 +136,7 @@ let encoding =
     case ~tag:0x50
       ~title:"Get_operation_hashes_for_blocks"
       (obj1 (req "get_operation_hashes_for_blocks"
-               (list (tup2 Block_hash.encoding int8))))
+               (list ~max_length:10 (tup2 Block_hash.encoding int8))))
       (function
         | Get_operation_hashes_for_blocks keys -> Some keys
         | _ -> None)
@@ -159,9 +159,10 @@ let encoding =
     case ~tag:0x60
       ~title:"Get_operations_for_blocks"
       (obj1 (req "get_operations_for_blocks"
-               (list (obj2
-                        (req "hash" Block_hash.encoding)
-                        (req "validation_pass" int8)))))
+               (list ~max_length:10
+                  (obj2
+                     (req "hash" Block_hash.encoding)
+                     (req "validation_pass" int8)))))
       (function
         | Get_operations_for_blocks keys -> Some keys
         | _ -> None)