diff --git a/nettle-internal.h b/nettle-internal.h
index 03c501fd57ff58d7773ac05c3e54baa682041677..670d4373e17681d948ca05dd7cba60d777ccda41 100644
--- a/nettle-internal.h
+++ b/nettle-internal.h
@@ -38,7 +38,10 @@ extern const struct nettle_cipher nettle_des3;
 
 extern const struct nettle_cipher nettle_blowfish128;
 
-/* Glue to openssl, for comparative benchmarking */
+/* Glue to openssl, for comparative benchmarking. The corresponding
+ * code is not included in the nettle library, as that would make the
+ * shared library depend on openssl. Instead, look at
+ * examples/nettle-openssl.c. */
 extern const struct nettle_cipher nettle_openssl_blowfish128;
 extern const struct nettle_cipher nettle_openssl_des;
 extern const struct nettle_cipher nettle_openssl_cast128;