diff --git a/tljh-voila-gallery/tljh_voila_gallery/install_builder_units.py b/tljh-voila-gallery/tljh_voila_gallery/install_builder_units.py
index 340c26b..77f00a9 100644
--- a/tljh-voila-gallery/tljh_voila_gallery/install_builder_units.py
+++ b/tljh-voila-gallery/tljh_voila_gallery/install_builder_units.py
@@ -1,8 +1,12 @@
+import os
 import sys
 from pkg_resources import resource_stream
 
 from tljh import systemd
 
+GALLERY_REPO = os.environ.get('GALLERY_REPO', 'git+https://github.com/voila-gallery/gallery@master#"egg=tljh-voila-gallery&subdirectory=tljh-voila-gallery"')
+
+
 def ensure_builder_units():
     gallery_builder_service = 'tljh-voila-gallery-builder.service'
     with resource_stream(__name__, f'./systemd-units/{gallery_builder_service}') as f:
@@ -14,6 +18,7 @@ def ensure_builder_units():
 
     unit_params = dict(
         python_interpreter_path=sys.executable,
+        gallery_repo=GALLERY_REPO,
     )
 
     systemd.install_unit(gallery_builder_service, builder_unit_template.format(**unit_params))
diff --git a/tljh-voila-gallery/tljh_voila_gallery/systemd-units/tljh-voila-gallery-builder.service b/tljh-voila-gallery/tljh_voila_gallery/systemd-units/tljh-voila-gallery-builder.service
index 3117fe3..e9af183 100644
--- a/tljh-voila-gallery/tljh_voila_gallery/systemd-units/tljh-voila-gallery-builder.service
+++ b/tljh-voila-gallery/tljh_voila_gallery/systemd-units/tljh-voila-gallery-builder.service
@@ -11,6 +11,9 @@ PrivateTmp=yes
 PrivateDevices=yes
 ProtectKernelTunables=yes
 ProtectKernelModules=yes
+# Update with the new gallery
+ExecStartPre={python_interpreter_path} -m pip install -U {gallery_repo}
+# Build the new Docker images
 ExecStart={python_interpreter_path} -m tljh_voila_gallery.build_images
 
 [Install]