diff --git a/crypto/ossl_typ.h b/crypto/ossl_typ.h
index 08c2968f1..345fb1dc4 100644
--- a/crypto/ossl_typ.h
+++ b/crypto/ossl_typ.h
@@ -97,6 +97,7 @@ typedef int ASN1_NULL;
 
 #ifdef OPENSSL_SYS_WIN32
 #undef X509_NAME
+#undef X509_EXTENSIONS
 #undef X509_CERT_PAIR
 #undef PKCS7_ISSUER_AND_SERIAL
 #endif