diff --git a/tor2web/utils/ssl.py b/tor2web/utils/ssl.py
index 5aedbeb8..8ff20d5e 100644
--- a/tor2web/utils/ssl.py
+++ b/tor2web/utils/ssl.py
@@ -130,7 +130,7 @@ def cacheContext(self):
 
             ecdh = _lib.EC_KEY_new_by_curve_name(_lib.NID_X9_62_prime256v1)
             ecdh = _ffi.gc(ecdh, _lib.EC_KEY_free)
-            _lib.SSL_CTX_set_tmp_ecdh(ctx.context, ecdh)
+            _lib.SSL_CTX_set_tmp_ecdh(ctx._context, ecdh)
 
             self._context = ctx