diff --git a/tests/suites/test_suite_ssl_decrypt.function b/tests/suites/test_suite_ssl_decrypt.function
index 048093f..ad94a58 100644
--- a/tests/suites/test_suite_ssl_decrypt.function
+++ b/tests/suites/test_suite_ssl_decrypt.function
@@ -13,6 +13,113 @@
  * END_DEPENDENCIES
  */
 
+/* BEGIN_CASE depends_on:MBEDTLS_SSL_PROTO_TLS1_2:MBEDTLS_CIPHER_NULL_CIPHER */
+void ssl_decrypt_null(int hash_id)
+{
+    mbedtls_ssl_transform transform_in, transform_out;
+    mbedtls_ssl_transform_init(&transform_in);
+    mbedtls_ssl_transform_init(&transform_out);
+    const mbedtls_ssl_protocol_version version = MBEDTLS_SSL_VERSION_TLS1_2;
+    const mbedtls_cipher_type_t cipher_type = MBEDTLS_CIPHER_NULL;
+    mbedtls_record rec_good = {
+        .ctr = { 0 },
+        .type = MBEDTLS_SSL_MSG_APPLICATION_DATA,
+        .ver = { 0, 0 },    /* Will be set by a function call below */
+        .buf = NULL,
+        .buf_len = 0,
+        .data_offset = 0,
+        .data_len = 0,
+#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
+        .cid_len = 0,
+        .cid = { 0 },
+#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
+    };
+    mbedtls_ssl_write_version(rec_good.ver,
+                              MBEDTLS_SSL_TRANSPORT_STREAM,
+                              version);
+    const char sample_plaintext[3] = "ABC";
+    mbedtls_ssl_context ssl;
+    mbedtls_ssl_init(&ssl);
+    uint8_t *buf = NULL;
+
+    MD_OR_USE_PSA_INIT();
+
+    TEST_EQUAL(mbedtls_test_ssl_build_transforms(&transform_in, &transform_out,
+                                                 cipher_type, hash_id, 0, 0,
+                                                 version,
+                                                 0, 0), 0);
+
+    const size_t plaintext_length = sizeof(sample_plaintext);
+    rec_good.buf_len = plaintext_length + transform_in.maclen;
+    rec_good.data_len = plaintext_length;
+    TEST_CALLOC(rec_good.buf, rec_good.buf_len);
+    memcpy(rec_good.buf, sample_plaintext, plaintext_length);
+    TEST_EQUAL(mbedtls_test_ssl_prepare_record_mac(&rec_good,
+                                                   &transform_out), 0);
+
+    /* Good case */
+    mbedtls_record rec = rec_good;
+    TEST_EQUAL(mbedtls_ssl_decrypt_buf(&ssl, &transform_in, &rec), 0);
+
+    /* Change any one byte of the plaintext or MAC. The MAC will be wrong. */
+    TEST_CALLOC(buf, rec.buf_len);
+    for (size_t i = 0; i < rec.buf_len; i++) {
+        mbedtls_test_set_step(i);
+        rec = rec_good;
+        rec.buf = buf;
+        memcpy(buf, rec_good.buf, rec.buf_len);
+        buf[i] ^= 1;
+        TEST_EQUAL(mbedtls_ssl_decrypt_buf(&ssl, &transform_in, &rec),
+                   MBEDTLS_ERR_SSL_INVALID_MAC);
+    }
+    mbedtls_free(buf);
+    buf = NULL;
+
+    /* Shorter input buffer. Either the MAC will be wrong, or there isn't
+     * enough room for a MAC. */
+    for (size_t n = 1; n < rec.buf_len; n++) {
+        mbedtls_test_set_step(n);
+        rec = rec_good;
+        TEST_CALLOC(buf, n);
+        rec.buf = buf;
+        rec.buf_len = n;
+        rec.data_len = n;
+        memcpy(buf, rec_good.buf, n);
+        TEST_EQUAL(mbedtls_ssl_decrypt_buf(&ssl, &transform_in, &rec),
+                   MBEDTLS_ERR_SSL_INVALID_MAC);
+        mbedtls_free(buf);
+        buf = NULL;
+    }
+
+    /* For robustness, check a 0-length buffer (non-null, then null).
+     * This should not reach mbedtls_ssl_decrypt_buf() as used in the library,
+     * so the exact error doesn't matter, but we don't want a crash. */
+    {
+        const uint8_t buf1[1] = { 'a' };
+        rec = rec_good;
+        /* We won't write to buf1[0] since it's out of range, so we can cast
+         * the const away. */
+        rec.buf = (uint8_t *) buf1;
+        rec.buf_len = 0;
+        TEST_EQUAL(mbedtls_ssl_decrypt_buf(&ssl, &transform_in, &rec),
+                   MBEDTLS_ERR_SSL_INTERNAL_ERROR);
+    }
+    rec = rec_good;
+    rec.buf = NULL;
+    rec.buf_len = 0;
+    TEST_EQUAL(mbedtls_ssl_decrypt_buf(&ssl, &transform_in, &rec),
+               MBEDTLS_ERR_SSL_INTERNAL_ERROR);
+
+exit:
+    mbedtls_ssl_transform_free(&transform_in);
+    mbedtls_ssl_transform_free(&transform_out);
+    mbedtls_free(rec_good.buf);
+    mbedtls_ssl_free(&ssl);
+    mbedtls_free(buf);
+    MD_OR_USE_PSA_DONE();
+}
+/* END_CASE */
+
 /* BEGIN_CASE depends_on:MBEDTLS_CIPHER_MODE_CBC:MBEDTLS_AES_C:MBEDTLS_SSL_PROTO_TLS1_2 */
 void ssl_decrypt_non_etm_cbc(int cipher_type, int hash_id, int trunc_hmac,
                              int length_selector)
diff --git a/tests/suites/test_suite_ssl_decrypt.misc.data b/tests/suites/test_suite_ssl_decrypt.misc.data
index 6a75dd5..f663b26 100644
--- a/tests/suites/test_suite_ssl_decrypt.misc.data
+++ b/tests/suites/test_suite_ssl_decrypt.misc.data
@@ -1,3 +1,19 @@
+Decrypt null cipher, MD5
+depends_on:MBEDTLS_MD_CAN_MD5
+ssl_decrypt_null:MBEDTLS_MD_MD5
+
+Decrypt null cipher, SHA-1
+depends_on:MBEDTLS_MD_CAN_SHA1
+ssl_decrypt_null:MBEDTLS_MD_SHA1
+
+Decrypt null cipher, SHA-256
+depends_on:MBEDTLS_MD_CAN_SHA256
+ssl_decrypt_null:MBEDTLS_MD_SHA256
+
+Decrypt null cipher, SHA-384
+depends_on:MBEDTLS_MD_CAN_SHA384
+ssl_decrypt_null:MBEDTLS_MD_SHA384
+
 Decrypt CBC !EtM, AES MD5 !trunc, empty plaintext, minpad
 depends_on:MBEDTLS_AES_C:MBEDTLS_MD_CAN_MD5
 ssl_decrypt_non_etm_cbc:MBEDTLS_CIPHER_AES_128_CBC:MBEDTLS_MD_MD5:0:-1