diff --git a/docker/federation/run-federation-test.bash b/docker/federation/run-federation-test.bash
index 62bc1e8bf..2c8b681ce 100755
--- a/docker/federation/run-federation-test.bash
+++ b/docker/federation/run-federation-test.bash
@@ -3,6 +3,7 @@ set -e
 
 if [ "$1" = "-yarn" ]; then
   pushd ../../ui/ || exit
+  yarn
   yarn build
   popd || exit
 fi
@@ -13,4 +14,4 @@ popd || exit
 
 sudo docker build ../../ -f Dockerfile -t lemmy-federation:latest
 
-sudo docker-compose up
\ No newline at end of file
+sudo docker-compose up