diff --git a/src/enacl.erl b/src/enacl.erl
index d2ab386..6cb0770 100644
--- a/src/enacl.erl
+++ b/src/enacl.erl
@@ -649,7 +649,7 @@ sign_verify_detached(SIG, M, PK) ->
         false -> {error, failed_verification}
     end.
 
--type sign_state() :: {signstate, reference()}.
+-type sign_state() :: reference().
 
 %% @doc sign_init/0 initialize a multi-part signature state.
 %%
@@ -665,7 +665,7 @@ sign_init() ->
 -spec sign_update(S, M) -> sign_state() | {error, sign_update_error}
     when S :: sign_state(),
          M :: iodata().
-sign_update({signstate, SignState}, M) ->
+sign_update(SignState, M) ->
     enacl_nif:crypto_sign_update(SignState, M).
 
 
@@ -675,7 +675,7 @@ sign_update({signstate, SignState}, M) ->
 -spec sign_final_create(S, SK) -> {ok, binary()} | {error, atom()}
     when S :: sign_state(),
          SK :: iodata().
-sign_final_create({signstate, SignState}, SK) ->
+sign_final_create(SignState, SK) ->
     enacl_nif:crypto_sign_final_create(SignState, SK).
 
 %% @doc sign_final_verify/3 verify a chunked signature
@@ -687,7 +687,7 @@ sign_final_create({signstate, SignState}, SK) ->
     when S :: sign_state(),
          SIG :: binary(),
          PK :: iodata().
-sign_final_verify({signstate, SignState}, SIG, PK) ->
+sign_final_verify(SignState, SIG, PK) ->
     enacl_nif:crypto_sign_final_verify(SignState, SIG, PK).
 
 %% @private
diff --git a/test/enacl_SUITE.erl b/test/enacl_SUITE.erl
index eb4d5fa..0cb6f97 100644
--- a/test/enacl_SUITE.erl
+++ b/test/enacl_SUITE.erl
@@ -42,7 +42,8 @@ groups() ->
                      generichash_chunked,
                      aead_xchacha20poly1305,
                      aead_chacha20poly1305,
-                     pwhash]},
+                     pwhash,
+                     sign]},
 
     [Neg, Pos].
 
@@ -121,3 +122,20 @@ pwhash(_Config) ->
     true = enacl:pwhash_str_verify(Str1, PW),
     false = enacl:pwhash_str_verify(Str1, <<PW/binary, 1>>),
     ok.
+
+sign(_Config) ->
+    #{public := PK, secret := SK} = enacl:sign_keypair(),
+    Msg = <<"Test">>,
+    State = enacl:sign_init(),
+    Create = sign_chunked(State, Msg, 10000),
+    {ok, Signature} = enacl:sign_final_create(Create, SK),
+    StateVerify = enacl:sign_init(),
+    Verify = sign_chunked(StateVerify, Msg, 10000),
+    ok = enacl:sign_final_verify(Verify, Signature, PK),
+    ok.
+
+sign_chunked(S, _M, 0) -> S;
+sign_chunked(S, M, N) ->
+    S2 = enacl:sign_update(S, M),
+    sign_chunked(S2, M, N-1).
+