diff --git a/library/x509write_crt.c b/library/x509write_crt.c
index bac849f..4f23395 100644
--- a/library/x509write_crt.c
+++ b/library/x509write_crt.c
@@ -124,7 +124,7 @@
 }
 #endif // MBEDTLS_BIGNUM_C && !MBEDTLS_DEPRECATED_REMOVED
 
-int mbedtls_x509write_crt_set_serial_new(mbedtls_x509write_cert *ctx,
+int mbedtls_x509write_crt_set_serial_raw(mbedtls_x509write_cert *ctx,
                                          unsigned char *serial, size_t serial_len)
 {
     if (serial_len > MBEDTLS_X509_RFC5280_MAX_SERIAL_LEN) {