diff --git a/build.docker b/build.docker
index 2c455ec..b735438 100644
--- a/build.docker
+++ b/build.docker
@@ -1,2 +1,5 @@
 FROM golang:1.13
 
+RUN apt-get update && apt-get install -y \
+    rsync \
+ && rm -rf /var/lib/apt/lists/*