diff --git a/concourse/tasks/build-theia-package.sh b/concourse/tasks/build-theia-package.sh
index 368545633..606acf862 100755
--- a/concourse/tasks/build-theia-package.sh
+++ b/concourse/tasks/build-theia-package.sh
@@ -42,7 +42,7 @@ cd "$sources"
 ./build.sh
 cd "$ext_folder"
 tar_file=$extension_id-v$qualified_version.tgz
-yarn pack $tar_file
+yarn pack --filename $tar_file
 
 cp $tarfile $workdir/out