diff --git a/decrepit/x509/x509_decrepit.c b/decrepit/x509/x509_decrepit.c
new file mode 100644
index 0000000..5714b40
--- /dev/null
+++ b/decrepit/x509/x509_decrepit.c
@@ -0,0 +1,42 @@
+/* Copyright (c) 2016, Google Inc.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+ * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+ * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
+
+#include <openssl/conf.h>
+#include <openssl/x509v3.h>
+
+
+X509_EXTENSION *X509V3_EXT_conf_nid(LHASH_OF(CONF_VALUE) *conf,
+                                    X509V3_CTX *ctx, int ext_nid, char *value) {
+  CONF *nconf = NULL;
+  LHASH_OF(CONF_VALUE) *orig_data = NULL;
+
+  if (conf != NULL) {
+    nconf = NCONF_new(NULL /* no method */);
+    if (nconf == NULL) {
+      return NULL;
+    }
+
+    orig_data = nconf->data;
+    nconf->data = conf;
+  }
+
+  X509_EXTENSION *ret = X509V3_EXT_nconf_nid(nconf, ctx, ext_nid, value);
+
+  if (nconf != NULL) {
+    nconf->data = orig_data;
+    NCONF_free(nconf);
+  }
+
+  return ret;
+}