diff --git a/Dockerfile b/Dockerfile
index 4667362..f59e11b 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -3,5 +3,9 @@ USER root
 WORKDIR /build
 COPY . /build
 
+RUN gem update \
+    && gem install concurrent-ruby \
+    && bundle install
+
 WORKDIR /
 ENTRYPOINT [ "/build/bin/wayback_machine_downloader" ]
\ No newline at end of file