diff --git a/Dockerfile b/Dockerfile
index f3d6e7fa..02c97e1e 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM elixir:1.5
+FROM elixir:1.18.4
 RUN apt-get update && apt-get install -y inotify-tools
 WORKDIR /elixir-koans
 ADD . /elixir-koans/