diff --git a/tests/api/test_chacha20_poly1305.c b/tests/api/test_chacha20_poly1305.c
index 6f90c71712..921cf20b49 100644
--- a/tests/api/test_chacha20_poly1305.c
+++ b/tests/api/test_chacha20_poly1305.c
@@ -526,11 +526,11 @@ int test_wc_ChaCha20Poly1305_Stream(void)
     /* wc_ChaCha20Poly1305_Final: NULL aead */
     ExpectIntEQ(wc_ChaCha20Poly1305_Final(NULL, outTag),
         WC_NO_ERR_TRACE(BAD_FUNC_ARG));
-    /* wc_ChaCha20Poly1305_Final: wrong state (INIT, not AAD/DATA) */
+    /* wc_ChaCha20Poly1305_Final: READY state (Init, no UpdateAad/UpdateData)
+     * is valid -- RFC 8439 Section 2.8 permits empty plaintext + empty AAD. */
     ExpectIntEQ(wc_ChaCha20Poly1305_Init(&aead, key, iv,
         CHACHA20_POLY1305_AEAD_ENCRYPT), 0);
-    ExpectIntEQ(wc_ChaCha20Poly1305_Final(&aead, outTag),
-        WC_NO_ERR_TRACE(BAD_STATE_E));
+    ExpectIntEQ(wc_ChaCha20Poly1305_Final(&aead, outTag), 0);
 #endif
     return EXPECT_RESULT();
 } /* END test_wc_ChaCha20Poly1305_Stream */
diff --git a/wolfcrypt/src/chacha20_poly1305.c b/wolfcrypt/src/chacha20_poly1305.c
index 75b9b094d1..a53cec65e8 100644
--- a/wolfcrypt/src/chacha20_poly1305.c
+++ b/wolfcrypt/src/chacha20_poly1305.c
@@ -275,7 +275,8 @@ int wc_ChaCha20Poly1305_Final(ChaChaPoly_Aead* aead,
     if (aead == NULL || outAuthTag == NULL) {
         return BAD_FUNC_ARG;
     }
-    if (aead->state != CHACHA20_POLY1305_STATE_AAD &&
+    if (aead->state != CHACHA20_POLY1305_STATE_READY &&
+        aead->state != CHACHA20_POLY1305_STATE_AAD &&
         aead->state != CHACHA20_POLY1305_STATE_DATA) {
         return BAD_STATE_E;
     }
diff --git a/wolfcrypt/test/test.c b/wolfcrypt/test/test.c
index cd3275650b..0b32f05636 100644
--- a/wolfcrypt/test/test.c
+++ b/wolfcrypt/test/test.c
@@ -11790,6 +11790,22 @@ static wc_test_ret_t chacha20_poly1305_oneshot_test(void)
 
 static wc_test_ret_t chacha20_poly1305_stream_param_test(void)
 {
+    /* Wycheproof tc2: empty plaintext + empty AAD (valid per RFC 8439 Section 2.8) */
+    WOLFSSL_SMALL_STACK_STATIC const byte key_tc2[] = {
+        0x80, 0xba, 0x31, 0x92, 0xc8, 0x03, 0xce, 0x96,
+        0x5e, 0xa3, 0x71, 0xd5, 0xff, 0x07, 0x3c, 0xf0,
+        0xf4, 0x3b, 0x6a, 0x2a, 0xb5, 0x76, 0xb2, 0x08,
+        0x42, 0x6e, 0x11, 0x40, 0x9c, 0x09, 0xb9, 0xb0
+    };
+    WOLFSSL_SMALL_STACK_STATIC const byte iv_tc2[] = {
+        0x4d, 0xa5, 0xbf, 0x8d, 0xfd, 0x58, 0x52, 0xc1,
+        0xea, 0x12, 0x37, 0x9d
+    };
+    WOLFSSL_SMALL_STACK_STATIC const byte authTag_tc2[] = {
+        0x76, 0xac, 0xb3, 0x42, 0xcf, 0x31, 0x66, 0xa5,
+        0xb6, 0x3c, 0x0c, 0x0e, 0xa1, 0x38, 0x3c, 0x8d
+    };
+
     const byte* key1 = chacha20_poly1305_test1_key;
     const byte* iv1 = chacha20_poly1305_test1_iv;
     const byte* aad1 = chacha20_poly1305_test1_aad;
@@ -11863,10 +11879,16 @@ static wc_test_ret_t chacha20_poly1305_stream_param_test(void)
     err = wc_ChaCha20Poly1305_Final(&aead, generatedAuthTag);
     if (err != WC_NO_ERR_TRACE(BAD_STATE_E))
         return WC_TEST_RET_ENC_EC(err);
-    aead.state = CHACHA20_POLY1305_STATE_READY;
+    /* Wycheproof tc2: empty plaintext + empty AAD must succeed (RFC 8439 Section 2.8) */
+    err = wc_ChaCha20Poly1305_Init(&aead, key_tc2, iv_tc2,
+        CHACHA20_POLY1305_AEAD_ENCRYPT);
+    if (err != 0)
+        return WC_TEST_RET_ENC_EC(err);
     err = wc_ChaCha20Poly1305_Final(&aead, generatedAuthTag);
-    if (err != WC_NO_ERR_TRACE(BAD_STATE_E))
+    if (err != 0)
         return WC_TEST_RET_ENC_EC(err);
+    if (XMEMCMP(generatedAuthTag, authTag_tc2, sizeof(authTag_tc2)) != 0)
+        return WC_TEST_RET_ENC_NC;
 
     return 0;
 }