diff --git a/src/lib_base/block_locator.ml b/src/lib_base/block_locator.ml
index 6d69ca4a9..57f058ccc 100644
--- a/src/lib_base/block_locator.ml
+++ b/src/lib_base/block_locator.ml
@@ -65,20 +65,20 @@ module Step : sig
 
 end = struct
 
-  type state = int * int * Cstruct.t
+  type state = int * int * MBytes.t
 
   let init seed head =
-    let seed =
-      Nocrypto.Hash.digest `SHA256 @@
-      Cstruct.concat
-        [ Cstruct.of_bigarray @@ P2p_peer.Id.to_bytes seed.sender_id ;
-          Cstruct.of_bigarray @@ P2p_peer.Id.to_bytes seed.receiver_id ;
-          Cstruct.of_bigarray @@ Block_hash.to_bytes head ] in
-    (1, 9, seed)
+    let open Hacl.Hash in
+    let st = SHA256.init () in
+    List.iter (SHA256.update st) [
+      P2p_peer.Id.to_bytes seed.sender_id ;
+      P2p_peer.Id.to_bytes seed.receiver_id ;
+      Block_hash.to_bytes head ] ;
+    (1, 9, SHA256.finish st)
 
   let draw seed n =
-    Int32.to_int (MBytes.get_int32 (Cstruct.to_bigarray seed) 0) mod n,
-    Nocrypto.Hash.digest `SHA256 seed
+    Int32.to_int (MBytes.get_int32 seed 0) mod n,
+    Hacl.Hash.SHA256.digest seed
 
   let next (step, counter, seed) =
     let random_gap, seed =
diff --git a/src/lib_crypto/base58.ml b/src/lib_crypto/base58.ml
index db130c397..2436fa942 100644
--- a/src/lib_crypto/base58.ml
+++ b/src/lib_crypto/base58.ml
@@ -112,11 +112,9 @@ let raw_decode ?(alphabet=Alphabet.default) s =
 
 let checksum s =
   let hash =
-    Nocrypto.Hash.digest `SHA256 @@
-    Nocrypto.Hash.digest `SHA256 @@
-    Cstruct.of_string s in
+    Hacl.Hash.SHA256.(digest (digest (Bigstring.of_string s))) in
   let res = Bytes.make 4 '\000' in
-  Cstruct.blit_to_bytes hash 0 res 0 4 ;
+  Bigstring.blit_to_bytes hash 0 res 0 4 ;
   Bytes.to_string res
 
 (* Append a 4-bytes cryptographic checksum before encoding string s *)
diff --git a/src/lib_crypto/jbuild b/src/lib_crypto/jbuild
index db8edd1c2..099cdca8c 100644
--- a/src/lib_crypto/jbuild
+++ b/src/lib_crypto/jbuild
@@ -15,7 +15,6 @@
               tezos-rpc
               tezos-clic
               lwt
-              nocrypto
               blake2
               hacl
               secp256k1
diff --git a/src/lib_crypto/tezos-crypto.opam b/src/lib_crypto/tezos-crypto.opam
index 328c87e83..95983b15e 100644
--- a/src/lib_crypto/tezos-crypto.opam
+++ b/src/lib_crypto/tezos-crypto.opam
@@ -15,7 +15,6 @@ depends: [
   "tezos-rpc"
   "tezos-clic"
   "lwt"
-  "nocrypto"
   "blake2"
   "hacl"
   "zarith"