diff --git a/Dockerfile b/Dockerfile
index 9740b70..8130caf 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,2 +1,2 @@
 FROM codeberg.org/forgejo/forgejo:1.19
-RUN apk --no-cache add asciidoctor rouge
+RUN apk --no-cache add asciidoctor ruby-rouge