diff --git a/test/default/core_ed25519_h2c.c b/test/default/core_ed25519_h2c.c
index e4e65b98..020e9c98 100644
--- a/test/default/core_ed25519_h2c.c
+++ b/test/default/core_ed25519_h2c.c
@@ -4,20 +4,25 @@
 typedef struct TestData_ {
     int         ro;
     const char *msg;
+    const char  tv_x[64 + 1];
     const char  tv_y[64 + 1];
 } TestData;
 
 static TestData test_data[] = {
     { 0, "",
+      "1ff2b70ecf862799e11b7ae744e3489aa058ce805dd323a936375a84695e76da",
       "222e314d04a4d5725e9f2aff9fb2a6b69ef375a1214eb19021ceab2d687f0f9b" },
     { 0, "abc",
+      "5f13cc69c891d86927eb37bd4afc6672360007c63f68a33ab423a3aa040fd2a8",
       "67732d50f9a26f73111dd1ed5dba225614e538599db58ba30aaea1f5c827fa42" },
     { 0, "abcdef0123456789",
+      "1dd2fefce934ecfd7aae6ec998de088d7dd03316aa1847198aecf699ba6613f1",
       "2f8a6c24dd1adde73909cada6a4a137577b0f179d336685c4a955a0a8e1a86fb" },
     { 0,
       "q128_"
       "qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq"
       "qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq",
+      "35fbdc5143e8a97afd3096f2b843e07df72e15bfca2eaf6879bf97c5d3362f73",
       "2af6ff6ef5ebba128b0774f4296cb4c2279a074658b083b8dcca91f57a603450" },
     { 0,
       "a512_"
@@ -29,17 +34,22 @@ static TestData test_data[] = {
       "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
       "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
       "aaaaaaaa",
+      "6e5e1f37e99345887fc12111575fc1c3e36df4b289b8759d23af14d774b66bff",
       "2c90c3d39eb18ff291d33441b35f3262cdd307162cc97c31bfcc7a4245891a37" },
     { 1, "",
+      "3c3da6925a3c3c268448dcabb47ccde5439559d9599646a8260e47b1e4822fc6",
       "09a6c8561a0b22bef63124c588ce4c62ea83a3c899763af26d795302e115dc21" },
     { 1, "abc",
+      "608040b42285cc0d72cbb3985c6b04c935370c7361f4b7fbdb1ae7f8c1a8ecad",
       "1a8395b88338f22e435bbd301183e7f20a5f9de643f11882fb237f88268a5531" },
     { 1, "abcdef0123456789",
+      "6d7fabf47a2dc03fe7d47f7dddd21082c5fb8f86743cd020f3fb147d57161472",
       "53060a3d140e7fbcda641ed3cf42c88a75411e648a1add71217f70ea8ec561a6" },
     { 1,
       "q128_"
       "qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq"
       "qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq",
+      "5fb0b92acedd16f3bcb0ef83f5c7b7a9466b5f1e0d8d217421878ea3686f8524",
       "2eca15e355fcfa39d2982f67ddb0eea138e2994f5956ed37b7f72eea5e89d2f7" },
     { 1,
       "a512_"
@@ -51,6 +61,7 @@ static TestData test_data[] = {
       "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
       "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
       "aaaaaaaa",
+      "0efcfde5898a839b00997fbe40d2ebe950bc81181afbd5cd6b9618aa336c1e8c",
       "6dc2fc04f266c5c27f236a80b14f92ccd051ef1ff027f26a07f8c0f327d8f995" }
 };
 
@@ -59,12 +70,16 @@ static TestData test_data[] = {
 int
 main(void)
 {
+    unsigned char *expected_xr, *expected_x;
     unsigned char *expected_yr, *expected_y, *y;
+    unsigned char  expected_x_sign;
     char *         expected_y_hex, *y_hex;
     char *         oversized_ctx;
     size_t         i, j;
     size_t         oversized_ctx_len = 500U;
 
+    expected_xr = (unsigned char *) sodium_malloc(crypto_core_ed25519_BYTES);
+    expected_x  = (unsigned char *) sodium_malloc(crypto_core_ed25519_BYTES);
     expected_yr = (unsigned char *) sodium_malloc(crypto_core_ed25519_BYTES);
     expected_y  = (unsigned char *) sodium_malloc(crypto_core_ed25519_BYTES);
     y           = (unsigned char *) sodium_malloc(crypto_core_ed25519_BYTES);
@@ -72,6 +87,13 @@ main(void)
         (char *) sodium_malloc(crypto_core_ed25519_BYTES * 2U + 1U);
     y_hex = (char *) sodium_malloc(crypto_core_ed25519_BYTES * 2U + 1U);
     for (i = 0U; i < (sizeof test_data) / (sizeof test_data[0]); i++) {
+        sodium_hex2bin(expected_xr, crypto_core_ed25519_BYTES,
+                       test_data[i].tv_x, (size_t) -1U, NULL, NULL, NULL);
+        for (j = 0; j < crypto_core_ed25519_BYTES; j++) {
+            expected_x[j] = expected_xr[crypto_core_ed25519_BYTES - 1U - j];
+        }
+        expected_x_sign = expected_x[0] & 1;
+
         sodium_hex2bin(expected_yr, crypto_core_ed25519_BYTES,
                        test_data[i].tv_y, (size_t) -1U, NULL, NULL, NULL);
         for (j = 0; j < crypto_core_ed25519_BYTES; j++) {
@@ -92,6 +114,9 @@ main(void)
                 printf("crypto_core_ed25519_from_string_ro() failed\n");
             }
         }
+        if (((y[crypto_core_ed25519_BYTES - 1U] >> 7) & 1) != expected_x_sign) {
+            printf("Test #%u failed - x sign bit mismatch\n", (unsigned) i);
+        }
         y[crypto_core_ed25519_BYTES - 1U] &= 0x7f;
         if (memcmp(y, expected_y, crypto_core_ed25519_BYTES) != 0) {
             sodium_bin2hex(expected_y_hex, crypto_core_ed25519_BYTES * 2U + 1U,
@@ -135,6 +160,8 @@ main(void)
     sodium_free(y);
     sodium_free(expected_y);
     sodium_free(expected_yr);
+    sodium_free(expected_x);
+    sodium_free(expected_xr);
 
     printf("OK\n");