diff --git a/library/x509_internal.h b/library/x509_internal.h
index dc56bf6..9360471 100644
--- a/library/x509_internal.h
+++ b/library/x509_internal.h
@@ -44,8 +44,7 @@
                          mbedtls_x509_buf *ext, int tag);
 #if !defined(MBEDTLS_X509_REMOVE_INFO)
 int mbedtls_x509_sig_alg_gets(char *buf, size_t size, const mbedtls_x509_buf *sig_oid,
-                              mbedtls_pk_type_t pk_alg, mbedtls_md_type_t md_alg,
-                              const void *sig_opts);
+                              mbedtls_pk_type_t pk_alg, mbedtls_md_type_t md_alg);
 #endif
 int mbedtls_x509_key_size_helper(char *buf, size_t buf_size, const char *name);
 int mbedtls_x509_set_extension(mbedtls_asn1_named_data **head, const char *oid, size_t oid_len,