diff --git a/rallly/hooks/init b/rallly/hooks/init
index ae52654..055affd 100755
--- a/rallly/hooks/init
+++ b/rallly/hooks/init
@@ -2,6 +2,8 @@
 
 set -e
 
+version_gt() { test "$(echo "$@" | tr " " "\n" | sort -V | head -n 1)" != "$1"; }
+
 ## bug: https://github.com/adoptium/containers/issues/215#issuecomment-1142046045
 docker_version=$(docker info --format '{{.ServerVersion}}')
 if ! version_gt "$docker_version" 20.10.0; then