diff --git a/dockerfiles/swh-objstorage/Dockerfile b/dockerfiles/swh-objstorage/Dockerfile
--- a/dockerfiles/swh-objstorage/Dockerfile
+++ b/dockerfiles/swh-objstorage/Dockerfile
@@ -1,6 +1,6 @@
 FROM python:3
 
-export DEBIAN_FRONTEND=noninteractive && \
+RUN export DEBIAN_FRONTEND=noninteractive && \
   apt-get update && \
   apt-get install -y \
     libsystemd-dev
diff --git a/dockerfiles/swh-storage/Dockerfile b/dockerfiles/swh-storage/Dockerfile
--- a/dockerfiles/swh-storage/Dockerfile
+++ b/dockerfiles/swh-storage/Dockerfile
@@ -1,6 +1,6 @@
 FROM python:3
 
-export DEBIAN_FRONTEND=noninteractive && \
+RUN export DEBIAN_FRONTEND=noninteractive && \
   apt-get update && \
   apt-get install -y \
     libsystemd-dev postgresql-client