diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1b6adab..40caac7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -14,7 +14,6 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Implement missing EQC tests
   - stream_chacha20...
   - stream_xor...
-  - generichash...
 
 ## [Unreleased]
 
diff --git a/c_src/generichash.c b/c_src/generichash.c
index 4da2c80..a554d43 100644
--- a/c_src/generichash.c
+++ b/c_src/generichash.c
@@ -96,8 +96,8 @@ ERL_NIF_TERM enacl_crypto_generichash(ErlNifEnv *env, int argc,
 
   // Verify that hash size is
   // crypto_generichash_BYTES/crypto_generichash_BYTES_MIN/crypto_generichash_BYTES_MAX
-  if ((hash_size <= crypto_generichash_BYTES_MIN) ||
-      (hash_size >= crypto_generichash_BYTES_MAX)) {
+  if ((hash_size < crypto_generichash_BYTES_MIN) ||
+      (hash_size > crypto_generichash_BYTES_MAX)) {
     goto bad_arg;
   }
 
@@ -105,8 +105,8 @@ ERL_NIF_TERM enacl_crypto_generichash(ErlNifEnv *env, int argc,
   unsigned char *k = key.data;
   if (0 == key.size) {
     k = NULL;
-  } else if (key.size <= crypto_generichash_KEYBYTES_MIN ||
-             key.size >= crypto_generichash_KEYBYTES_MAX) {
+  } else if (key.size < crypto_generichash_KEYBYTES_MIN ||
+             key.size > crypto_generichash_KEYBYTES_MAX) {
     goto bad_arg;
   }
 
@@ -150,8 +150,8 @@ ERL_NIF_TERM enacl_crypto_generichash_init(ErlNifEnv *env, int argc,
     goto bad_arg;
 
   // Verify that hash size is valid
-  if ((hash_size <= crypto_generichash_BYTES_MIN) ||
-      (hash_size >= crypto_generichash_BYTES_MAX)) {
+  if ((hash_size < crypto_generichash_BYTES_MIN) ||
+      (hash_size > crypto_generichash_BYTES_MAX)) {
     goto bad_arg;
   }
 
@@ -159,8 +159,8 @@ ERL_NIF_TERM enacl_crypto_generichash_init(ErlNifEnv *env, int argc,
   unsigned char *k = key.data;
   if (0 == key.size) {
     k = NULL;
-  } else if (key.size <= crypto_generichash_KEYBYTES_MIN ||
-             key.size >= crypto_generichash_KEYBYTES_MAX) {
+  } else if (key.size < crypto_generichash_KEYBYTES_MIN ||
+             key.size > crypto_generichash_KEYBYTES_MAX) {
     goto bad_arg;
   }
 
diff --git a/eqc_test/enacl_eqc.erl b/eqc_test/enacl_eqc.erl
index 4371ff8..1610f4b 100644
--- a/eqc_test/enacl_eqc.erl
+++ b/eqc_test/enacl_eqc.erl
@@ -140,6 +140,17 @@ kx_keypair_bad() ->
     end
   end).
 
+g_generichash_data() ->
+  binary().
+
+g_generichash_key() ->
+  ?LET({Min, Max}, {return(enacl_nif:crypto_generichash_KEYBYTES_MIN()), return(enacl_nif:crypto_generichash_KEYBYTES_MAX())},
+    largebinary({limit, Min, Max})).
+
+g_generichash_size() ->
+  ?LET({Min, Max}, {return(enacl_nif:crypto_generichash_BYTES_MIN()), return(enacl_nif:crypto_generichash_BYTES_MAX())},
+    choose(Min, Max)).
+
 %% CRYPTO BOX
 %% ---------------------------
 %% * box/4
@@ -798,6 +809,22 @@ prop_crypto_shorthash_eq() ->
         end
       end
     ).
+prop_crypto_generichash_eq() ->
+  ?FORALL({Sz, X, Key}, {g_generichash_size(), g_generichash_data(), g_generichash_key()},
+      equals(enacl:generichash(Sz, X, Key), enacl:generichash(Sz, X, Key))).
+
+generichash_loop(S, []) -> S;
+generichash_loop(S, [M|Ms]) ->
+  S2 = enacl:generichash_update(S, M),
+  generichash_loop(S2, Ms).
+
+prop_crypto_generichash_multi_part_eq() ->
+  ?FORALL({Sz, Xs, Key}, {g_generichash_size(), list(g_generichash_data()), g_generichash_key()},
+  begin
+    S1 = generichash_loop(enacl:generichash_init(Sz, Key), Xs),
+    S2 = generichash_loop(enacl:generichash_init(Sz, Key), Xs),
+    equals(enacl:generichash_final(S1), enacl:generichash_final(S2))
+  end).
 
 prop_crypto_shorthash_neq() ->
   ?FORALL({X, Y}, diff_pair(),