diff --git a/test/default/core_ed25519.c b/test/default/core_ed25519.c
index 13aef00e..f031e364 100644
--- a/test/default/core_ed25519.c
+++ b/test/default/core_ed25519.c
@@ -23,15 +23,22 @@ add_P(unsigned char * const S)
         0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
         0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x7f
     };
-    unsigned char c = 0U;
-    unsigned int  i;
-    unsigned int  s;
 
-    for (i = 0U; i < 32U; i++) {
-        s = S[i] + P[i] + c;
-        S[i] = (unsigned char) s;
-        c = (s >> 8) & 1;
-    }
+    sodium_add(S, P, sizeof P);
+}
+
+static void
+add_l64(unsigned char * const S)
+{
+    static const unsigned char l[64] =
+      { 0xed, 0xd3, 0xf5, 0x5c, 0x1a, 0x63, 0x12, 0x58,
+        0xd6, 0x9c, 0xf7, 0xa2, 0xde, 0xf9, 0xde, 0x14,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10,
+        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
+
+    sodium_add(S, l, sizeof l);
 }
 
 int
@@ -40,6 +47,7 @@ main(void)
     unsigned char *h;
     unsigned char *p, *p2, *p3;
     unsigned char *sc;
+    unsigned char *sc64;
     int            i, j;
 
     h = (unsigned char *) sodium_malloc(crypto_core_ed25519_UNIFORMBYTES);
@@ -152,6 +160,20 @@ main(void)
         assert(memcmp(p3, p, crypto_core_ed25519_BYTES) == 0);
     }
 
+    sc64 = (unsigned char *) sodium_malloc(64);
+    crypto_core_ed25519_scalar_random(sc);
+    memcpy(sc64, sc, crypto_core_ed25519_BYTES);
+    memset(sc64 + crypto_core_ed25519_BYTES, 0,
+           64 - crypto_core_ed25519_BYTES);
+    i = randombytes_uniform(100);
+    do {
+        add_l64(sc64);
+    } while (i-- > 0U);
+    crypto_core_ed25519_scalar_reduce(sc64, sc64);
+    if (memcmp(sc64, sc, crypto_core_ed25519_BYTES) != 0) {
+        printf("crypto_core_ed25519_scalar_reduce() failed\n");
+    }
+
     sodium_free(sc);
     sodium_free(p3);
     sodium_free(p2);
diff --git a/test/default/misuse.c b/test/default/misuse.c
index 97ccbf2c..8767c5e9 100644
--- a/test/default/misuse.c
+++ b/test/default/misuse.c
@@ -54,7 +54,8 @@ sigabrt_handler_11(int sig)
 {
     (void) sig;
     signal(SIGABRT, sigabrt_handler_12);
-    assert(crypto_box_easy(guard_page, guard_page, crypto_stream_xsalsa20_MESSAGEBYTES_MAX,
+    assert(crypto_box_easy(guard_page, guard_page,
+                           crypto_stream_xsalsa20_MESSAGEBYTES_MAX,
                            guard_page, guard_page, guard_page) == -1);
     exit(1);
 }
@@ -64,7 +65,8 @@ sigabrt_handler_10(int sig)
 {
     (void) sig;
     signal(SIGABRT, sigabrt_handler_11);
-    assert(crypto_box_easy_afternm(guard_page, guard_page, crypto_stream_xsalsa20_MESSAGEBYTES_MAX,
+    assert(crypto_box_easy_afternm(guard_page, guard_page,
+                                   crypto_stream_xsalsa20_MESSAGEBYTES_MAX,
                                    guard_page, guard_page) == -1);
     exit(1);
 }
@@ -74,7 +76,8 @@ sigabrt_handler_9(int sig)
 {
     (void) sig;
     signal(SIGABRT, sigabrt_handler_10);
-    assert(sodium_base642bin(guard_page, 1, guard_page, 1, NULL, NULL, NULL, -1) == -1);
+    assert(sodium_base642bin(guard_page, 1, guard_page, 1,
+                             NULL, NULL, NULL, -1) == -1);
     exit(1);
 }
 
@@ -83,7 +86,8 @@ sigabrt_handler_8(int sig)
 {
     (void) sig;
     signal(SIGABRT, sigabrt_handler_9);
-    assert(sodium_bin2base64(guard_page, 1, guard_page, 1, sodium_base64_VARIANT_ORIGINAL) == NULL);
+    assert(sodium_bin2base64(guard_page, 1, guard_page, 1,
+                             sodium_base64_VARIANT_ORIGINAL) == NULL);
     exit(1);
 }
 
@@ -111,7 +115,8 @@ sigabrt_handler_5(int sig)
     (void) sig;
     signal(SIGABRT, sigabrt_handler_6);
     assert(crypto_aead_xchacha20poly1305_ietf_encrypt(guard_page, NULL, NULL, UINT64_MAX,
-                                                      NULL, 0, NULL, guard_page, NULL) == -1);
+                                                      NULL, 0, NULL,
+                                                      guard_page, guard_page) == -1);
     exit(1);
 }
 
@@ -121,7 +126,8 @@ sigabrt_handler_4(int sig)
     (void) sig;
     signal(SIGABRT, sigabrt_handler_5);
     assert(crypto_aead_chacha20poly1305_ietf_encrypt(guard_page, NULL, NULL, UINT64_MAX,
-                                                     NULL, 0, NULL, guard_page, NULL) == -1);
+                                                     NULL, 0, NULL,
+                                                     guard_page, guard_page) == -1);
     exit(1);
 }
 
@@ -131,7 +137,8 @@ sigabrt_handler_3(int sig)
     (void) sig;
     signal(SIGABRT, sigabrt_handler_4);
     assert(crypto_aead_chacha20poly1305_encrypt(guard_page, NULL, NULL, UINT64_MAX,
-                                                NULL, 0, NULL, guard_page, NULL) == -1);
+                                                NULL, 0, NULL,
+                                                guard_page, guard_page) == -1);
     exit(1);
 }
 
@@ -153,7 +160,8 @@ sigabrt_handler_1(int sig)
 {
     (void) sig;
     signal(SIGABRT, sigabrt_handler_2);
-    assert(crypto_kx_server_session_keys(NULL, NULL, guard_page, guard_page, guard_page) == -1);
+    assert(crypto_kx_server_session_keys(NULL, NULL, guard_page, guard_page,
+                                         guard_page) == -1);
     exit(1);
 }
 
@@ -161,7 +169,8 @@ int
 main(void)
 {
     signal(SIGABRT, sigabrt_handler_1);
-    assert(crypto_kx_client_session_keys(NULL, NULL, guard_page, guard_page, guard_page) == -1);
+    assert(crypto_kx_client_session_keys(NULL, NULL, guard_page, guard_page,
+                                         guard_page) == -1);
     return 1;
 }
 #else