diff --git a/nettle-internal.h b/nettle-internal.h
index 5771829ce95d966485009aca5df8ea0b5c97d18d..03c501fd57ff58d7773ac05c3e54baa682041677 100644
--- a/nettle-internal.h
+++ b/nettle-internal.h
@@ -38,4 +38,9 @@ extern const struct nettle_cipher nettle_des3;
 
 extern const struct nettle_cipher nettle_blowfish128;
 
+/* Glue to openssl, for comparative benchmarking */
+extern const struct nettle_cipher nettle_openssl_blowfish128;
+extern const struct nettle_cipher nettle_openssl_des;
+extern const struct nettle_cipher nettle_openssl_cast128;
+
 #endif /* NETTLE_INTERNAL_H_INCLUDED */