diff --git a/action.yml b/action.yml
index 3da2a50..66149f8 100644
--- a/action.yml
+++ b/action.yml
@@ -32,7 +32,7 @@ runs:
 
         email=''
         name=''
-        user=${USER,,}
+        user=$(echo $USER | tr [A-Z] [a-z])
         if [ $user = 'actions-user' ]; then
           email='65916846+actions-user@users.noreply.github.com'
           name='actions-user'
@@ -50,7 +50,7 @@ runs:
         echo "email: $email"
 
         flag='--local'
-        if [ ${GLOBAL,,} = 'true' ]; then
+        if [ $(echo $GLOBAL | tr [A-Z] [a-z]) = 'true' ]; then
           flag='--global'
         fi
         echo "flag: $flag"