diff --git a/tests/api/test_curve448.c b/tests/api/test_curve448.c
index 170ac54fb3..83fd0f8c37 100644
--- a/tests/api/test_curve448.c
+++ b/tests/api/test_curve448.c
@@ -1106,8 +1106,17 @@ int test_wc_curve448_cryptocb(void)
 
     wc_curve448_free(&keyB);
 #ifndef WC_NO_CONSTRUCTORS
+    /* result_code and key_p are both optional */
+    {
+        curve448_key* keyC = NULL;
+        ExpectNotNull(keyC = wc_curve448_new(HEAP_HINT, devId, NULL));
+        if (keyC != NULL) {
+            DoExpectIntEQ(wc_curve448_delete(keyC, NULL), 0);
+        }
+    }
     if (keyA != NULL) {
         DoExpectIntEQ(wc_curve448_delete(keyA, &keyA), 0);
+        ExpectNull(keyA);
     }
     ExpectIntEQ(wc_curve448_delete(NULL, NULL),
         WC_NO_ERR_TRACE(BAD_FUNC_ARG));
diff --git a/wolfcrypt/src/curve448.c b/wolfcrypt/src/curve448.c
index 653a119832..058b7f44cc 100644
--- a/wolfcrypt/src/curve448.c
+++ b/wolfcrypt/src/curve448.c
@@ -342,9 +342,9 @@ int wc_curve448_shared_secret_ex(curve448_key* private_key,
     wc_MemZero_Add("wc_curve448_shared_secret_ex o", o, CURVE448_PUB_KEY_SIZE);
 #endif
 
-    if (ret == 0) {
-        ret = curve448(o, private_key->k, public_key->p);
-    }
+    /* ret is 0 here: the argument checks return early and the cryptocb block
+     * either returns or resets it. */
+    ret = curve448(o, private_key->k, public_key->p);
 #ifndef WOLFSSL_NO_ECDHX_SHARED_ZERO_CHECK
     if (ret == 0) {
         byte t = 0;
diff --git a/wolfcrypt/test/test.c b/wolfcrypt/test/test.c
index 335d936114..0a70c61bf8 100644
--- a/wolfcrypt/test/test.c
+++ b/wolfcrypt/test/test.c
@@ -80467,7 +80467,10 @@ static wc_test_ret_t curve448_onlycb_test(myCryptoDevCtx *ctx)
     ret = wc_curve448_make_key(&rng, CURVE448_KEY_SIZE, &key);
     if (ret != 0)
         ret = WC_TEST_RET_ENC_EC(ret);
-    else if (!key.privSet || !key.pubSet || (key.p[0] != 0xC3) ||
+    else if (!key.privSet || !key.pubSet ||
+             !curve448_buf_is(key.p, 0xC3, CURVE448_PUB_KEY_SIZE) ||
+             (key.k[0] != 0x58) ||
+             !curve448_buf_is(key.k + 1, 0x5A, CURVE448_KEY_SIZE - 2) ||
              (key.k[CURVE448_KEY_SIZE-1] != 0xDA))
         ret = WC_TEST_RET_ENC_NC;
 
@@ -80557,7 +80560,8 @@ static wc_test_ret_t curve448_onlycb_test(myCryptoDevCtx *ctx)
         ret = wc_curve448_shared_secret(&key, &pubKey, out, &outLen);
         if (ret != 0)
             ret = WC_TEST_RET_ENC_EC(ret);
-        else if ((outLen != CURVE448_KEY_SIZE) || (out[0] != 0xA5))
+        else if ((outLen != CURVE448_KEY_SIZE) ||
+                 !curve448_buf_is(out, 0xA5, CURVE448_PUB_KEY_SIZE))
             ret = WC_TEST_RET_ENC_NC;
     }
     if (ret == 0) {
@@ -81206,12 +81210,12 @@ static int myCryptoDevCb(int devIdArg, wc_CryptoInfo* info, void* ctx)
             printf("CryptoDevCb: exampleVar %d\n", myCtx->exampleVar);
             #endif
             if (myCtx->exampleVar == 99) {
+                info->pk.curve448kg.key->devId = devIdArg;
                 /* the dispatcher must hand over a usable payload */
                 if ((info->pk.curve448kg.rng == NULL) ||
                     (info->pk.curve448kg.size != CURVE448_KEY_SIZE)) {
                     return BAD_FUNC_ARG;
                 }
-                info->pk.curve448kg.key->devId = devIdArg;
                 /* deterministic key material so the caller can prove the
                  * callback's output actually reached it */
                 XMEMSET(info->pk.curve448kg.key->k, 0x5A, CURVE448_KEY_SIZE);