diff --git a/src/_cffi_src/openssl/x509.py b/src/_cffi_src/openssl/x509.py
index 28f00da..aa8a8e7 100644
--- a/src/_cffi_src/openssl/x509.py
+++ b/src/_cffi_src/openssl/x509.py
@@ -282,6 +282,7 @@
 int i2d_re_X509_tbs(X509 *, unsigned char **);
 void X509_get0_signature(ASN1_BIT_STRING **, X509_ALGOR **, X509 *);
 int X509_get_signature_nid(const X509 *);
+X509_ALGOR *X509_get0_tbs_sigalg(X509 *);
 
 long X509_get_version(X509 *);
 
@@ -428,6 +429,12 @@
 /* Added in 1.1.0 but we need it in all versions now due to the great
    opaquing. */
 #if OPENSSL_VERSION_NUMBER < 0x10100000L || defined(LIBRESSL_VERSION_NUMBER)
+
+X509_ALGOR *X509_get0_tbs_sigalg(X509 *x)
+{
+    return x->cert_info->signature;
+}
+
 /* from x509/x509_req.c */
 void X509_REQ_get0_signature(ASN1_BIT_STRING **psig, X509_ALGOR **palg,
                              X509_REQ *req)