diff --git a/update_test_binaries.sh b/update_test_binaries.sh
index 5470bec87d63bf4666a5c0286b005fbdc8699e87..4740a95f2176241d1154e5a83b941336e126d71a 100755
--- a/update_test_binaries.sh
+++ b/update_test_binaries.sh
@@ -3,6 +3,7 @@
 set -ex
 
 branch=master
+workdir=${TMPDIR:-/tmp}
 
 usage()
 {
@@ -11,7 +12,7 @@ usage()
 	echo "    -l, --release RELEASE_VERSION  The release version to download packages/binaries from (see https://repositories.apertis.org/apertis/dists/)"
 	echo "    -r, --repository REPOSITORY    The name of the repository to update (under https://gitlab.apertis.org/tests)"
 	echo "    -b, --branch BRANCH            The branch in the repository to push the changes to (default: master)"
-	echo "    -w, --workdir WORKDIR          The workdir (default: current dir)"
+	echo "    -w, --workdir WORKDIR          The workdir (default: $workdir)"
 	echo "    -n, --dry-run                  Do not attempt to push changes to repository (default: push)"
 	echo "    -h, --help                     Display this help and exit"
 }