diff --git a/README.md b/README.md
index 42e1df841371f11c0ed1a8a70144b5deb57b0b3f..2ea5808660a01e427c3153ad2fc6579826fbe16f 100644
--- a/README.md
+++ b/README.md
@@ -42,4 +42,4 @@ Released under the GPLv3 License (see [LICENSE](https://github.com/mooch443/trex
 
 # Reference
 
-A preprint is available at https://preprint.trex.run/.
+A preprint is available at http://preprint.trex.run/.