diff --git a/Dockerfile b/Dockerfile
index 8bc677e..9106ec1 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -17,6 +17,7 @@ RUN echo \
       "$(. /etc/os-release && echo "$VERSION_CODENAME")" stable" | \
       tee /etc/apt/sources.list.d/docker.list > /dev/null
 
+RUN apt-get update
 RUN apt-get install -y docker-ce-cli
 
 # Install tea