diff --git a/test/default/sign.c b/test/default/sign.c
index b711027b..bb5ca988 100644
--- a/test/default/sign.c
+++ b/test/default/sign.c
@@ -1054,6 +1054,8 @@ int main(void)
 {
     unsigned char      sm[1024 + crypto_sign_BYTES];
     unsigned char      m[1024];
+    unsigned char      skpk[crypto_sign_SECRETKEYBYTES +
+                            crypto_sign_PUBLICKEYBYTES];
     unsigned char      pk[crypto_sign_PUBLICKEYBYTES];
     unsigned char      sk[crypto_sign_SECRETKEYBYTES];
     char               pk_hex[crypto_sign_PUBLICKEYBYTES * 2 + 1];
@@ -1063,9 +1065,11 @@ int main(void)
     unsigned int       i;
 
     for (i = 0U; i < (sizeof test_data) / (sizeof test_data[0]); i++) {
+        memcpy(skpk, test_data[i].sk, crypto_sign_SECRETKEYBYTES_WITHOUT_PK);
+        memcpy(skpk + crypto_sign_SECRETKEYBYTES_WITHOUT_PK,
+               test_data[i].pk, crypto_sign_PUBLICKEYBYTES);
         if (crypto_sign(sm, &smlen,
-                        (const unsigned char *) test_data[i].m, i,
-                        test_data[i].sk) != 0) {
+                        (const unsigned char *) test_data[i].m, i, skpk) != 0) {
             printf("crypto_sign() failure: [%u]\n", i);
             continue;
         }