diff --git a/beta/args-gui b/beta/args-gui
index f0c7e03..84ad4dd 100644
--- a/beta/args-gui
+++ b/beta/args-gui
@@ -1,5 +1,5 @@
 -working working
--extern extern
+-extern /tmp/extern
 -db db
 -arch input
 -devDesc devDesc.yaml
diff --git a/beta/docker-run.sh b/beta/docker-run.sh
index 09ce8b4..ce72270 100755
--- a/beta/docker-run.sh
+++ b/beta/docker-run.sh
@@ -12,12 +12,14 @@
 # N.b. Using grphics in Docker is somewhat fiddly.
 # the following command works for me (Rob Adams).
 
+DATA=extern
 TAG=ghcr.io/iti/pcesapps-beta
 
 docker run -it --rm  \
 	--env DISPLAY=$DISPLAY \
 	-v /tmp/.X11-unix:/tmp/.X11-unix \
 	-v ${XAUTHORITY:-$HOME/.Xauthority}:/root/.Xauthority:ro \
+	-v $(pwd)/$DATA:/tmp/extern \
 	--net=host \
 	$TAG