diff --git a/.gitignore b/.gitignore
index ef9853af..e0281ae9 100644
--- a/.gitignore
+++ b/.gitignore
@@ -114,6 +114,7 @@ test/default/hash3
 test/default/kdf
 test/default/keygen
 test/default/kx
+test/default/misuse
 test/default/onetimeauth
 test/default/onetimeauth2
 test/default/onetimeauth7
diff --git a/src/libsodium/crypto_stream/salsa20/stream_salsa20.c b/src/libsodium/crypto_stream/salsa20/stream_salsa20.c
index 91e99df7..1a126dad 100644
--- a/src/libsodium/crypto_stream/salsa20/stream_salsa20.c
+++ b/src/libsodium/crypto_stream/salsa20/stream_salsa20.c
@@ -89,5 +89,5 @@ _crypto_stream_salsa20_pick_best_implementation(void)
         return 0;
     }
 #endif
-    return 0;
+    return 0; /* LCOV_EXCL_LINE */
 }
diff --git a/src/libsodium/sodium/core.c b/src/libsodium/sodium/core.c
index 5a06f69e..d550e079 100644
--- a/src/libsodium/sodium/core.c
+++ b/src/libsodium/sodium/core.c
@@ -41,11 +41,11 @@ int
 sodium_init(void)
 {
     if (sodium_crit_enter() != 0) {
-        return -1;
+        return -1; /* LCOV_EXCL_LINE */
     }
     if (initialized != 0) {
         if (sodium_crit_leave() != 0) {
-            return -1;
+            return -1; /* LCOV_EXCL_LINE */
         }
         return 1;
     }
@@ -60,7 +60,7 @@ sodium_init(void)
     _crypto_stream_salsa20_pick_best_implementation();
     initialized = 1;
     if (sodium_crit_leave() != 0) {
-        return -1;
+        return -1; /* LCOV_EXCL_LINE */
     }
     return 0;
 }
@@ -95,7 +95,7 @@ int
 sodium_crit_enter(void)
 {
     if (_sodium_crit_init() != 0) {
-        return -1;
+        return -1; /* LCOV_EXCL_LINE */
     }
     EnterCriticalSection(&_sodium_lock);
 
@@ -191,10 +191,10 @@ int
 sodium_set_misuse_handler(void (*handler)(const char *err))
 {
     if (sodium_crit_enter() != 0) {
-        return -1;
+        return -1; /* LCOV_EXCL_LINE */
     }
     _misuse_handler = handler;
     if (sodium_crit_leave() != 0) {
-        return -1;
+        return -1; /* LCOV_EXCL_LINE */
     }
 }
diff --git a/src/libsodium/sodium/utils.c b/src/libsodium/sodium/utils.c
index 0cb651ab..121e6a3e 100644
--- a/src/libsodium/sodium/utils.c
+++ b/src/libsodium/sodium/utils.c
@@ -68,8 +68,8 @@ __attribute__((weak)) void
 _sodium_dummy_symbol_to_prevent_memzero_lto(void *const  pnt,
                                             const size_t len)
 {
-    (void) pnt;
-    (void) len;
+    (void) pnt; /* LCOV_EXCL_LINE */
+    (void) len; /* LCOV_EXCL_LINE */
 }
 #endif
 
diff --git a/test/default/Makefile.am b/test/default/Makefile.am
index db117202..2cda92e4 100644
--- a/test/default/Makefile.am
+++ b/test/default/Makefile.am
@@ -37,6 +37,7 @@ EXTRA_DIST = \
 	kdf.exp \
 	keygen.exp \
 	kx.exp \
+	misuse.exp \
 	onetimeauth.exp \
 	onetimeauth2.exp \
 	onetimeauth7.exp \
@@ -106,6 +107,7 @@ DISTCLEANFILES = \
 	kdf.res \
 	keygen.res \
 	kx.res \
+	misuse.res \
 	onetimeauth.res \
 	onetimeauth2.res \
 	onetimeauth7.res \
@@ -176,6 +178,7 @@ CLEANFILES = \
 	kdf.final \
 	keygen.final \
 	kx.final \
+	misuse.final \
 	onetimeauth.final \
 	onetimeauth2.final \
 	onetimeauth7.final \
@@ -241,6 +244,7 @@ CLEANFILES = \
 	kdf.nexe \
 	keygen.nexe \
 	kx.nexe \
+	misuse.nexe \
 	onetimeauth.nexe \
 	onetimeauth2.nexe \
 	onetimeauth7.nexe \
@@ -318,6 +322,7 @@ TESTS_TARGETS = \
 	kdf \
 	keygen \
 	kx \
+	misuse \
 	onetimeauth \
 	onetimeauth2 \
 	onetimeauth7 \
@@ -460,6 +465,9 @@ keygen_LDADD              = $(TESTS_LDADD)
 kx_SOURCE                 = cmptest.h kx.c
 kx_LDADD                  = $(TESTS_LDADD)
 
+misuse_SOURCE             = cmptest.h misuse.c
+misuse_LDADD              = $(TESTS_LDADD)
+
 onetimeauth_SOURCE        = cmptest.h onetimeauth.c
 onetimeauth_LDADD         = $(TESTS_LDADD)
 
diff --git a/test/default/aead_xchacha20poly1305.c b/test/default/aead_xchacha20poly1305.c
index de2d445d..e20a8d70 100644
--- a/test/default/aead_xchacha20poly1305.c
+++ b/test/default/aead_xchacha20poly1305.c
@@ -29,6 +29,7 @@ tv(void)
         = { 0x50, 0x51, 0x52, 0x53, 0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7 };
     unsigned char *c = (unsigned char *) sodium_malloc(CLEN);
     unsigned char *detached_c = (unsigned char *) sodium_malloc(MLEN);
+    unsigned char *key2 = (unsigned char *) sodium_malloc(crypto_aead_xchacha20poly1305_ietf_KEYBYTES);
     unsigned char *mac = (unsigned char *) sodium_malloc(crypto_aead_xchacha20poly1305_ietf_ABYTES);
     unsigned char *m2 = (unsigned char *) sodium_malloc(MLEN);
     unsigned long long found_clen;
@@ -161,8 +162,15 @@ tv(void)
         printf("m != c (adlen=0)\n");
     }
 
+    crypto_aead_xchacha20poly1305_ietf_keygen(key2);
+    if (crypto_aead_xchacha20poly1305_ietf_decrypt(c, &m2len, NULL, c, CLEN,
+                                                  NULL, 0U, nonce, key2) == 0) {
+        printf("crypto_aead_xchacha20poly1305_ietf_decrypt() with a wrong key should have failed\n");
+    }
+
     sodium_free(c);
     sodium_free(detached_c);
+    sodium_free(key2);
     sodium_free(mac);
     sodium_free(m2);
     sodium_free(m);
diff --git a/test/default/chacha20.c b/test/default/chacha20.c
index 3cba6c31..facd6e60 100644
--- a/test/default/chacha20.c
+++ b/test/default/chacha20.c
@@ -172,8 +172,13 @@ main(void)
     tv_ietf();
 
     assert(crypto_stream_chacha20_keybytes() > 0U);
+    assert(crypto_stream_chacha20_keybytes() == crypto_stream_chacha20_KEYBYTES);
     assert(crypto_stream_chacha20_noncebytes() > 0U);
+    assert(crypto_stream_chacha20_noncebytes() == crypto_stream_chacha20_NONCEBYTES);
+    assert(crypto_stream_chacha20_ietf_keybytes() > 0U);
+    assert(crypto_stream_chacha20_ietf_keybytes() == crypto_stream_chacha20_ietf_KEYBYTES);
     assert(crypto_stream_chacha20_ietf_noncebytes() > 0U);
+    assert(crypto_stream_chacha20_ietf_noncebytes() == crypto_stream_chacha20_ietf_NONCEBYTES);
 
     return 0;
 }
diff --git a/test/default/kdf.c b/test/default/kdf.c
index 211cc4af..48225c5a 100644
--- a/test/default/kdf.c
+++ b/test/default/kdf.c
@@ -19,8 +19,8 @@ tv_kdf(void)
     }
     subkey = (unsigned char *) sodium_malloc(crypto_kdf_BYTES_MAX);
     for (i = 0; i < 10; i++) {
-        assert(crypto_kdf_blake2b_derive_from_key(subkey, crypto_kdf_BYTES_MAX,
-                                                  i, context, master_key) == 0);
+        assert(crypto_kdf_derive_from_key(subkey, crypto_kdf_BYTES_MAX,
+                                          i, context, master_key) == 0);
         sodium_bin2hex(hex, sizeof hex, subkey, crypto_kdf_BYTES_MAX);
         printf("%s\n", hex);
     }
@@ -28,8 +28,8 @@ tv_kdf(void)
 
     for (i = 0; i < crypto_kdf_BYTES_MAX + 2; i++) {
         subkey = (unsigned char *) sodium_malloc(crypto_kdf_BYTES_MAX);
-        if (crypto_kdf_blake2b_derive_from_key(subkey, (size_t) i,
-                                               i, context, master_key) == 0) {
+        if (crypto_kdf_derive_from_key(subkey, (size_t) i,
+                                       i, context, master_key) == 0) {
             sodium_bin2hex(hex, sizeof hex, subkey, (size_t) i);
             printf("%s\n", hex);
         } else {
@@ -48,6 +48,10 @@ tv_kdf(void)
     assert(crypto_kdf_contextbytes() == crypto_kdf_CONTEXTBYTES);
     assert(crypto_kdf_KEYBYTES >= 16);
     assert(crypto_kdf_keybytes() == crypto_kdf_KEYBYTES);
+    assert(crypto_kdf_bytes_min() == crypto_kdf_blake2b_bytes_min());
+    assert(crypto_kdf_bytes_max() == crypto_kdf_blake2b_bytes_max());
+    assert(crypto_kdf_contextbytes() == crypto_kdf_blake2b_contextbytes());
+    assert(crypto_kdf_keybytes() == crypto_kdf_blake2b_keybytes());
 
     printf("tv_kdf: ok\n");
 }
diff --git a/test/default/misuse.c b/test/default/misuse.c
new file mode 100644
index 00000000..ff49e418
--- /dev/null
+++ b/test/default/misuse.c
@@ -0,0 +1,50 @@
+
+#define TEST_NAME "misuse"
+#include "cmptest.h"
+
+#include <signal.h>
+
+static void
+sigabrt_handler_3(int sig)
+{
+    (void) sig;
+    exit(0);
+}
+
+static void
+sigabrt_handler_2(int sig)
+{
+    (void) sig;
+    signal(SIGABRT, sigabrt_handler_3);
+#if SIZE_MAX > 0x4000000000ULL
+    randombytes_buf_deterministic(NULL, 0x4000000001ULL, NULL);
+#else
+    abort();
+#endif
+    exit(1);
+}
+
+static void
+sigabrt_handler_1(int sig)
+{
+    (void) sig;
+    signal(SIGABRT, sigabrt_handler_2);
+    assert(crypto_kx_server_session_keys(NULL, NULL, NULL, NULL, NULL) == -1);
+    exit(1);
+}
+
+#if defined(SIGABRT) && !defined(__EMSCRIPTEN__) && !defined(__native_client__)
+int
+main(void)
+{
+    signal(SIGABRT, sigabrt_handler_1);
+    assert(crypto_kx_client_session_keys(NULL, NULL, NULL, NULL, NULL) == -1);
+    return 1;
+}
+#else
+int
+main(void)
+{
+    exit(0);
+}
+#endif
diff --git a/test/default/misuse.exp b/test/default/misuse.exp
new file mode 100644
index 00000000..e69de29b
diff --git a/test/default/onetimeauth.c b/test/default/onetimeauth.c
index 0bd60669..7a4931b4 100644
--- a/test/default/onetimeauth.c
+++ b/test/default/onetimeauth.c
@@ -56,6 +56,8 @@ main(void)
     assert(crypto_onetimeauth_poly1305_bytes() == crypto_onetimeauth_bytes());
     assert(crypto_onetimeauth_poly1305_keybytes() ==
            crypto_onetimeauth_keybytes());
+    assert(crypto_onetimeauth_statebytes() > 0);
+    assert(crypto_onetimeauth_statebytes() == crypto_onetimeauth_poly1305_statebytes());
 
     return 0;
 }
diff --git a/test/default/pwhash.c b/test/default/pwhash.c
index 00f3a157..8531cbf4 100644
--- a/test/default/pwhash.c
+++ b/test/default/pwhash.c
@@ -157,6 +157,10 @@ tv2(void)
                       1ULL << 12, 0) != -1) {
         printf("[tv2] pwhash should have failed (0)\n");
     }
+    if (crypto_pwhash_argon2i(out, sizeof out, "password", strlen("password"), salt, 3,
+                              1ULL << 12, 0) != -1) {
+        printf("[tv2] pwhash should have failed (0')\n");
+    }
     if (crypto_pwhash(out, sizeof out, "password", strlen("password"), salt, 3,
                       1, crypto_pwhash_alg_default()) != -1) {
         printf("[tv2] pwhash should have failed (1)\n");
@@ -408,6 +412,9 @@ main(void)
            crypto_pwhash_argon2i_alg_argon2i13());
     assert(crypto_pwhash_alg_argon2i13() == crypto_pwhash_ALG_ARGON2I13);
     assert(crypto_pwhash_alg_argon2i13() == crypto_pwhash_alg_default());
+    assert(crypto_pwhash_alg_argon2id13() == crypto_pwhash_ALG_ARGON2ID13);
+    assert(crypto_pwhash_alg_argon2id13() != crypto_pwhash_alg_argon2i13());
+    assert(crypto_pwhash_alg_argon2id13() != crypto_pwhash_alg_default());
 
     sodium_free(salt);
     sodium_free(str_out);
diff --git a/test/default/pwhash_argon2id.c b/test/default/pwhash_argon2id.c
index 9fa57f86..2e7a94cc 100644
--- a/test/default/pwhash_argon2id.c
+++ b/test/default/pwhash_argon2id.c
@@ -257,6 +257,9 @@ main(void)
     if (crypto_pwhash_argon2id_str_verify(str_out, passwd, strlen(passwd)) != 0) {
         printf("pwhash_argon2id_str_verify(1) failure\n");
     }
+    if (crypto_pwhash_str_verify(str_out, passwd, strlen(passwd)) != 0) {
+        printf("pwhash_argon2id_str_verify(1') failure\n");
+    }
     str_out[14]++;
     if (crypto_pwhash_argon2id_str_verify(str_out, passwd, strlen(passwd)) != -1) {
         printf("pwhash_argon2id_str_verify(2) failure\n");
@@ -309,26 +312,22 @@ main(void)
                                           "password", strlen("password")) != -1) {
         printf("pwhash_argon2id_str_verify(invalid(6)) failure\n");
     }
-    if (crypto_pwhash_argon2id_str_verify(
-                                          "$argon2id$v=19$m=256,t=3,p=1$MDEyMzQ1Njc"
-                                          "$G5ajKFCoUzaXRLdz7UJb5wGkb2Xt+X5/GQjUYtS2+TE",
-                                          "password", strlen("password")) != 0) {
+    if (crypto_pwhash_str_verify("$argon2id$v=19$m=256,t=3,p=1$MDEyMzQ1Njc"
+                                 "$G5ajKFCoUzaXRLdz7UJb5wGkb2Xt+X5/GQjUYtS2+TE",
+                                 "password", strlen("password")) != 0) {
         printf("pwhash_argon2id_str_verify(valid(7)) failure\n");
     }
-    if (crypto_pwhash_argon2id_str_verify(
-                                          "$argon2id$v=19$m=256,t=3,p=1$MDEyMzQ1Njc"
+    if (crypto_pwhash_argon2id_str_verify("$argon2id$v=19$m=256,t=3,p=1$MDEyMzQ1Njc"
                                           "$G5ajKFCoUzaXRLdz7UJb5wGkb2Xt+X5/GQjUYtS2+TE",
                                           "passwore", strlen("passwore")) != -1 || errno != EINVAL) {
         printf("pwhash_argon2id_str_verify(invalid(7)) failure\n");
     }
-    if (crypto_pwhash_argon2id_str_verify(
-                                          "$Argon2id$v=19$m=256,t=3,p=1$MDEyMzQ1Njc"
+    if (crypto_pwhash_argon2id_str_verify("$Argon2id$v=19$m=256,t=3,p=1$MDEyMzQ1Njc"
                                           "$G5ajKFCoUzaXRLdz7UJb5wGkb2Xt+X5/GQjUYtS2+TE",
                                           "password", strlen("password")) != -1 || errno != EINVAL) {
         printf("pwhash_argon2id_str_verify(invalid(8)) failure\n");
     }
-    if (crypto_pwhash_argon2id_str_verify(
-                                          "$argon2id$v=19$m=256,t=3,p=2$MDEyMzQ1Njc"
+    if (crypto_pwhash_argon2id_str_verify("$argon2id$v=19$m=256,t=3,p=2$MDEyMzQ1Njc"
                                           "$G5ajKFCoUzaXRLdz7UJb5wGkb2Xt+X5/GQjUYtS2+TE",
                                           "password", strlen("password")) != -1 || errno != EINVAL) {
         printf("pwhash_argon2id_str_verify(invalid(9)) failure\n");
diff --git a/test/default/secretbox.c b/test/default/secretbox.c
index 45a3fbdf..cf5823e2 100644
--- a/test/default/secretbox.c
+++ b/test/default/secretbox.c
@@ -55,6 +55,11 @@ main(void)
     }
     printf("\n");
 
+    assert(crypto_secretbox(c, c, 31, nonce, firstkey) == -1);
+    assert(crypto_secretbox(c, c, 12, nonce, firstkey) == -1);
+    assert(crypto_secretbox(c, c, 1, nonce, firstkey) == -1);
+    assert(crypto_secretbox(c, c, 0, nonce, firstkey) == -1);
+
     assert(crypto_secretbox_keybytes() > 0U);
     assert(crypto_secretbox_noncebytes() > 0U);
     assert(crypto_secretbox_zerobytes() > 0U);
diff --git a/test/default/secretbox2.c b/test/default/secretbox2.c
index 3e5247b3..e6320b77 100644
--- a/test/default/secretbox2.c
+++ b/test/default/secretbox2.c
@@ -46,5 +46,10 @@ main(void)
         }
         printf("\n");
     }
+    assert(crypto_secretbox_open(m, c, 31, nonce, firstkey) == -1);
+    assert(crypto_secretbox_open(m, c, 16, nonce, firstkey) == -1);
+    assert(crypto_secretbox_open(m, c, 1, nonce, firstkey) == -1);
+    assert(crypto_secretbox_open(m, c, 0, nonce, firstkey) == -1);
+
     return 0;
 }
diff --git a/test/default/xchacha20.c b/test/default/xchacha20.c
index b3936b9c..0074e827 100644
--- a/test/default/xchacha20.c
+++ b/test/default/xchacha20.c
@@ -229,7 +229,8 @@ tv_secretbox_xchacha20poly1305(void)
             (crypto_secretbox_xchacha20poly1305_MACBYTES + m_len);
         sodium_hex2bin(out, crypto_secretbox_xchacha20poly1305_MACBYTES + m_len,
                        tv->out, strlen(tv->out), NULL, NULL, NULL);
-        crypto_secretbox_xchacha20poly1305_easy(out2, m, m_len, nonce, key);
+        assert(crypto_secretbox_xchacha20poly1305_easy(out2, m, m_len, nonce, key) == 0);
+        assert(crypto_secretbox_xchacha20poly1305_easy(out2, m, SIZE_MAX, nonce, key) == -1);
         assert(memcmp(out, out2,
                       crypto_secretbox_xchacha20poly1305_MACBYTES + m_len) == 0);
         n = randombytes_uniform(crypto_secretbox_xchacha20poly1305_MACBYTES + m_len);
@@ -246,10 +247,18 @@ tv_secretbox_xchacha20poly1305(void)
         assert(crypto_secretbox_xchacha20poly1305_open_easy
                (out2, out2, crypto_secretbox_xchacha20poly1305_MACBYTES + m_len,
                 nonce, key) == 0);
+        assert(crypto_secretbox_xchacha20poly1305_open_easy
+               (out2, out2, crypto_secretbox_xchacha20poly1305_MACBYTES - 1,
+                nonce, key) == -1);
+        assert(crypto_secretbox_xchacha20poly1305_open_easy
+               (out2, out2, 0, nonce, key) == -1);
         assert(memcmp(m, out2, m_len) == 0);
         assert(crypto_secretbox_xchacha20poly1305_open_detached
                (out2, out + crypto_secretbox_xchacha20poly1305_MACBYTES, out,
                 m_len, nonce, key) == 0);
+        assert(crypto_secretbox_xchacha20poly1305_open_detached
+               (NULL, out + crypto_secretbox_xchacha20poly1305_MACBYTES, out,
+                m_len, nonce, key) == 0);
         crypto_secretbox_xchacha20poly1305_detached
             (out2 + crypto_secretbox_xchacha20poly1305_MACBYTES, out2, m,
              m_len, nonce, key);
@@ -302,6 +311,8 @@ tv_box_xchacha20poly1305(void)
         assert(crypto_box_curve25519xchacha20poly1305_keypair(pk, sk) == 0);
         assert(crypto_box_curve25519xchacha20poly1305_easy(out, m, m_len, nonce,
                                                            pk, sk) == 0);
+        assert(crypto_box_curve25519xchacha20poly1305_easy(out, m, SIZE_MAX, nonce,
+                                                           pk, sk) == -1);
         assert(crypto_box_curve25519xchacha20poly1305_open_easy
                (m2, out, crypto_box_curve25519xchacha20poly1305_MACBYTES + m_len,
                 nonce, pk, sk) == 0);
@@ -311,6 +322,8 @@ tv_box_xchacha20poly1305(void)
         out = (unsigned char *) sodium_malloc
             (crypto_box_curve25519xchacha20poly1305_MACBYTES + m_len);
         assert(crypto_box_curve25519xchacha20poly1305_beforenm(pc, pk, sk) == 0);
+        assert(crypto_box_curve25519xchacha20poly1305_easy_afternm
+               (out, m, SIZE_MAX, nonce, pc) == -1);
         assert(crypto_box_curve25519xchacha20poly1305_easy_afternm
                (out, m, m_len, nonce, pc) == 0);
         assert(crypto_box_curve25519xchacha20poly1305_open_easy_afternm
@@ -360,6 +373,7 @@ tv_box_xchacha20poly1305(void)
     assert(crypto_box_curve25519xchacha20poly1305_secretkeybytes() == crypto_box_curve25519xchacha20poly1305_SECRETKEYBYTES);
     assert(crypto_box_curve25519xchacha20poly1305_beforenmbytes() == crypto_box_curve25519xchacha20poly1305_BEFORENMBYTES);
     assert(crypto_box_curve25519xchacha20poly1305_noncebytes() == crypto_box_curve25519xchacha20poly1305_NONCEBYTES);
+    assert(crypto_box_curve25519xchacha20poly1305_macbytes() == crypto_box_curve25519xchacha20poly1305_MACBYTES);
 
     printf("tv_box_xchacha20poly1305: ok\n");
 }