diff --git a/scripts/glpi-change.sh b/scripts/glpi-change.sh
index cceff4d..43044a7 100755
--- a/scripts/glpi-change.sh
+++ b/scripts/glpi-change.sh
@@ -58,7 +58,7 @@ done
 
 set -a; . "$ENV_FILE"; set +a
 BASE="${GLPI_URL%/}"
-[ -n "${GLPI_USER_TOKEN:-}" ] && [ -n "${GLPI_APP_TOKEN:-}" ] || die "tokens missing in $ENV_FILE"
+if [ -z "${GLPI_USER_TOKEN:-}" ] || [ -z "${GLPI_APP_TOKEN:-}" ]; then die "tokens missing in $ENV_FILE"; fi
 
 sess_request() {
     curl -s -m 30 -H "Content-Type: application/json" \
@@ -131,7 +131,7 @@ create)
     ;;
 transition)
     cid="${args[0]:-}"; status="${args[1]:-}"
-    [ -n "$cid" ] && [ -n "$status" ] || die "usage: transition <change-id> <status-int>"
+    if [ -z "" ] || [ -z "" ]; then die "usage: transition <change-id> <status-int>"; fi
     body="$(mktemp)"
     jq -n --argjson s "$status" '{input: {status: $s}}' > "$body"
     resp="$(api PUT "Change/$cid" "$body")"