diff --git a/alpine/apps/gitea-act_runner/gitea-act_runner.sh b/alpine/apps/gitea-act_runner/gitea-act_runner.sh
index 557a45b..c0e046f 100644
--- a/alpine/apps/gitea-act_runner/gitea-act_runner.sh
+++ b/alpine/apps/gitea-act_runner/gitea-act_runner.sh
@@ -45,7 +45,8 @@ SelectImages() {
 				"archlinux-base-devel") IMAGES=${IMAGES}'"archlinux-base-devel:docker://archlinux:base-devel",';;
 			esac
 		done
-		IMAGES=$(printf '%s' "${IMAGES}" | cut -c 1)
+		# shellcheck disable=SC3057
+		IMAGES=${IMAGES::-1}
 	fi
 }
 SelectImages