diff --git a/lib/utils.sh b/lib/utils.sh
index 611f99e0..010c09f4 100644
--- a/lib/utils.sh
+++ b/lib/utils.sh
@@ -5,6 +5,8 @@ GREP_OPTIONS="--color=never"
 # shellcheck disable=SC2034
 GREP_COLORS=
 
+ASDF_DIR=${ASDF_DIR:-''}
+
 asdf_version() {
   cat "$(asdf_dir)/VERSION"
 }