diff --git a/test/default/core_ed25519.c b/test/default/core_ed25519.c
index 782291b3..b6bdfab9 100644
--- a/test/default/core_ed25519.c
+++ b/test/default/core_ed25519.c
@@ -312,13 +312,27 @@ main(void)
     crypto_core_ed25519_scalar_add(sc, sc2, sc);
     sodium_bin2hex(hex, crypto_core_ed25519_SCALARBYTES * 2 + 1,
                    sc, crypto_core_ed25519_SCALARBYTES);
-    printf("add: %s\n", hex);
+    printf("add1: %s\n", hex);
 
     crypto_core_ed25519_scalar_sub(sc, sc2, sc);
     crypto_core_ed25519_scalar_sub(sc, sc, sc2);
     sodium_bin2hex(hex, crypto_core_ed25519_SCALARBYTES * 2 + 1,
                    sc, crypto_core_ed25519_SCALARBYTES);
-    printf("sub: %s\n", hex);
+    printf("sub1: %s\n", hex);
+
+    memset(sc, 0xcd, crypto_core_ed25519_UNIFORMBYTES);
+    memset(sc2, 0x42, crypto_core_ed25519_UNIFORMBYTES);
+    crypto_core_ed25519_scalar_add(sc, sc, sc2);
+    crypto_core_ed25519_scalar_add(sc, sc2, sc);
+    sodium_bin2hex(hex, crypto_core_ed25519_SCALARBYTES * 2 + 1,
+                   sc, crypto_core_ed25519_SCALARBYTES);
+    printf("add2: %s\n", hex);
+
+    crypto_core_ed25519_scalar_sub(sc, sc2, sc);
+    crypto_core_ed25519_scalar_sub(sc, sc, sc2);
+    sodium_bin2hex(hex, crypto_core_ed25519_SCALARBYTES * 2 + 1,
+                   sc, crypto_core_ed25519_SCALARBYTES);
+    printf("sub2: %s\n", hex);
 
     sodium_free(hex);
     sodium_free(sc64);
diff --git a/test/default/core_ed25519.exp b/test/default/core_ed25519.exp
index 6b8c1686..89fbaa33 100644
--- a/test/default/core_ed25519.exp
+++ b/test/default/core_ed25519.exp
@@ -10,6 +10,8 @@ comp1: e56b69758fd3193097398c9717b11e48111112131415161718191a1b1c1d1e0f
 comp2: 09688ce78a8ff8273f636b0bc748c0cceeeeedecebeae9e8e7e6e5e4e3e2e100
 comp3: ceb4d73ffe47f83ebe85e18dcae6cc03f0f0f1f2f3f4f5f6f7f8f9fafbfcfd0e
 comp4: 201f1e1d1c1b1a191817161514131211100f0e0d0c0b0a090807060504030201
-add: f7567cd87c82ec1c355a6304c143bcc9ecedededededededededededededed0d
-sub: f67c79849de0253ba142949e1db6224b13121212121212121212121212121202
+add1: f7567cd87c82ec1c355a6304c143bcc9ecedededededededededededededed0d
+sub1: f67c79849de0253ba142949e1db6224b13121212121212121212121212121202
+add2: b02e8581ce62f69922427c23f970f7e951525252525252525252525252525202
+sub2: 3da570db4b001cbeb35a7b7fe588e72aaeadadadadadadadadadadadadadad0d
 OK