diff --git a/src/_cffi_src/openssl/x509v3.py b/src/_cffi_src/openssl/x509v3.py
index dae98da1bf4e..5dafabc3a89c 100644
--- a/src/_cffi_src/openssl/x509v3.py
+++ b/src/_cffi_src/openssl/x509v3.py
@@ -41,6 +41,8 @@
     } d;
     ...;
 } GENERAL_NAME;
+
+static const long X509V3_EXT_ERROR_UNKNOWN;
 """