diff --git a/Dockerfile b/Dockerfile
index 45103a5..d9100b8 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -4,3 +4,6 @@ FROM squidfunk/mkdocs-material
 # Beispiel; https://squidfunk.github.io/mkdocs-material/getting-started/
 # hadolint ignore=DL3013
 RUN pip install --no-cache-dir mkdocs-macros-plugin
+
+# hadolint ignore=DL3018
+RUN apk add --no-cache rsync