diff --git a/src/x509.c b/src/x509.c
index 0780601e4..a84ba4335 100644
--- a/src/x509.c
+++ b/src/x509.c
@@ -7460,6 +7460,7 @@ int wolfSSL_i2d_X509(WOLFSSL_X509* x509, unsigned char** out)
 {
     const unsigned char* der;
     int derSz = 0;
+    int advance = 1;
 
     WOLFSSL_ENTER("wolfSSL_i2d_X509");
 
@@ -7480,10 +7481,14 @@ int wolfSSL_i2d_X509(WOLFSSL_X509* x509, unsigned char** out)
             WOLFSSL_LEAVE("wolfSSL_i2d_X509", MEMORY_E);
             return MEMORY_E;
         }
+        advance = 0;
     }
 
-    if (out != NULL)
+    if (out != NULL) {
         XMEMCPY(*out, der, derSz);
+        if (advance)
+            *out += derSz;
+    }
 
     WOLFSSL_LEAVE("wolfSSL_i2d_X509", derSz);
     return derSz;
diff --git a/tests/api.c b/tests/api.c
index a3759296c..9d0f35931 100644
--- a/tests/api.c
+++ b/tests/api.c
@@ -53016,6 +53016,31 @@ static int test_wolfSSL_X509_load_crl_file(void)
     return EXPECT_RESULT();
 }
 
+static int test_wolfSSL_i2d_X509(void)
+{
+    EXPECT_DECLS;
+#if defined(OPENSSL_EXTRA) && defined(USE_CERT_BUFFERS_2048) && !defined(NO_RSA)
+    const unsigned char* cert_buf = server_cert_der_2048;
+    unsigned char* out = NULL;
+    unsigned char* tmp = NULL;
+    X509* cert = NULL;
+
+    ExpectNotNull(d2i_X509(&cert, &cert_buf, sizeof_server_cert_der_2048));
+    /* Pointer should be advanced */
+    ExpectPtrGT(cert_buf, server_cert_der_2048);
+    ExpectIntGT(i2d_X509(cert, &out), 0);
+    ExpectNotNull(out);
+    tmp = out;
+    ExpectIntGT(i2d_X509(cert, &tmp), 0);
+    ExpectPtrGT(tmp, out);
+
+    if (out != NULL)
+        XFREE(out, NULL, DYNAMIC_TYPE_OPENSSL);
+    X509_free(cert);
+#endif
+    return EXPECT_RESULT();
+}
+
 static int test_wolfSSL_d2i_X509_REQ(void)
 {
     EXPECT_DECLS;
@@ -67715,6 +67740,7 @@ TEST_CASE testCases[] = {
     TEST_DECL(test_wolfSSL_X509_set_version),
     TEST_DECL(test_wolfSSL_X509_get_serialNumber),
     TEST_DECL(test_wolfSSL_X509_CRL),
+    TEST_DECL(test_wolfSSL_i2d_X509),
     TEST_DECL(test_wolfSSL_d2i_X509_REQ),
     TEST_DECL(test_wolfSSL_PEM_read_X509),
     TEST_DECL(test_wolfSSL_X509_check_ca),