diff --git a/docker/backend/Dockerfile b/docker/backend/Dockerfile
index 84805d522..419a9cf5c 100644
--- a/docker/backend/Dockerfile
+++ b/docker/backend/Dockerfile
@@ -1,11 +1,12 @@
 FROM devfra.azurecr.io/de.fraport.build/tools:1.1.0
 
+# debug info
 RUN lsb_release -a
 
-RUN apt-get -y install inotify-tools
-RUN apt-get -y install haskell-stack git
-RUN apt-get -y install alex g++ happy libghc-zlib-dev libpq-dev libsodium-dev locales locales-all pkg-config
-RUN apt-get -y install llvm
+RUN apt-get -y update && apt-get -y install inotify-tools
+RUN apt-get -y update && apt-get -y install haskell-stack git
+RUN apt-get -y update && apt-get -y install alex g++ happy libghc-zlib-dev libpq-dev libsodium-dev locales locales-all pkg-config
+RUN apt-get -y update && apt-get -y install llvm
 
 ENV LANG=en_US.UTF-8