diff --git a/Dockerfile b/Dockerfile
index a75aab32..9e3e11d9 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -32,6 +32,7 @@ ARG NOVNC_REF=${NOVNC_REF:-v1.0.0}
 ARG SPICE_REPO=${SPICE_REPO:-https://gitlab.freedesktop.org/spice/spice-html5.git}
 ARG SPICE_REF=${SPICE_REF:-spice-html5-0.1.6}
 
+ADD data /tmp/
 COPY scripts /opt/loci/scripts
 ADD bindep.txt pydep.txt $EXTRA_BINDEP $EXTRA_PYDEP /opt/loci/
 
diff --git a/data/.gitignore b/data/.gitignore
new file mode 100644
index 00000000..d6b7ef32
--- /dev/null
+++ b/data/.gitignore
@@ -0,0 +1,2 @@
+*
+!.gitignore
diff --git a/scripts/clone_project.sh b/scripts/clone_project.sh
index 8809d8db..bb66e7c6 100755
--- a/scripts/clone_project.sh
+++ b/scripts/clone_project.sh
@@ -2,8 +2,10 @@
 
 set -eux
 
-git clone ${PROJECT_REPO} /tmp/${PROJECT}
-pushd /tmp/${PROJECT}
-git fetch ${PROJECT_REPO} ${PROJECT_REF}
-git checkout FETCH_HEAD
-popd
+if [[ ! -d /tmp/${PROJECT} ]]; then
+  git clone ${PROJECT_REPO} /tmp/${PROJECT}
+  pushd /tmp/${PROJECT}
+  git fetch ${PROJECT_REPO} ${PROJECT_REF}
+  git checkout FETCH_HEAD
+  popd
+fi