diff --git a/test/default/kdf.c b/test/default/kdf.c
index 48225c5a..8716de08 100644
--- a/test/default/kdf.c
+++ b/test/default/kdf.c
@@ -10,6 +10,7 @@ tv_kdf(void)
     char          *context;
     char           hex[crypto_kdf_BYTES_MAX * 2 + 1];
     uint64_t       i;
+    int            ret;
 
     context = (char *) sodium_malloc(crypto_kdf_CONTEXTBYTES);
     memcpy(context, "KDF test", strlen("KDF test"));
@@ -19,8 +20,9 @@ tv_kdf(void)
     }
     subkey = (unsigned char *) sodium_malloc(crypto_kdf_BYTES_MAX);
     for (i = 0; i < 10; i++) {
-        assert(crypto_kdf_derive_from_key(subkey, crypto_kdf_BYTES_MAX,
-                                          i, context, master_key) == 0);
+        ret = crypto_kdf_derive_from_key(subkey, crypto_kdf_BYTES_MAX,
+                                         i, context, master_key);
+        assert(ret == 0);
         sodium_bin2hex(hex, sizeof hex, subkey, crypto_kdf_BYTES_MAX);
         printf("%s\n", hex);
     }