diff --git a/cryptography/hazmat/backends/openssl/x509.py b/cryptography/hazmat/backends/openssl/x509.py
index 632efb3..ea46256 100644
--- a/cryptography/hazmat/backends/openssl/x509.py
+++ b/cryptography/hazmat/backends/openssl/x509.py
@@ -175,7 +175,7 @@
 int sk_X509_EXTENSION_num(X509_EXTENSIONS *);
 X509_EXTENSION *sk_X509_EXTENSION_value(X509_EXTENSIONS *, int);
 int sk_X509_EXTENSION_push(X509_EXTENSIONS *, X509_EXTENSION *);
-void sk_X509_EXTENSION_delete(X509_EXTENSIONS *, int);
+X509_EXTENSION *sk_X509_EXTENSION_delete(X509_EXTENSIONS *, int);
 void sk_X509_EXTENSION_free(X509_EXTENSIONS *);
 
 int sk_X509_REVOKED_num(struct stack_st_X509_REVOKED *);