diff --git a/0.17/files/docker-update-mods.sh b/0.17/files/docker-update-mods.sh
index 79b4097..8d953b4 100755
--- a/0.17/files/docker-update-mods.sh
+++ b/0.17/files/docker-update-mods.sh
@@ -9,10 +9,20 @@ if [[ -f /run/secrets/username ]]; then
   TOKEN=$(cat /run/secrets/token)
 fi
 
-if [[ -z $TOKEN ]]; then
-  set -- "$(jq -j ".username, \" \", .token" "$CONFIG/server-settings.json")"
-  USERNAME=$1
-  TOKEN=$2
+if [[ -z ${USERNAME:-} ]]; then
+  USERNAME="$(jq -j ".username" "$CONFIG/server-settings.json")"
+fi
+
+if [[ -z ${TOKEN:-} ]]; then
+  TOKEN="$(jq -j ".token" "$CONFIG/server-settings.json")"
+fi
+
+if [[ -z ${USERNAME:-} ]]; then
+  echo "You need to provide your Factorio username to update mods."
+fi
+
+if [[ -z ${TOKEN:-} ]]; then
+  echo "You need to provide your Factorio token to update mods."
 fi
 
 ./update-mods.sh "$VERSION" "$MODS" "$USERNAME" "$TOKEN"