diff --git a/luci/luci-app-qmodem/Makefile b/luci/luci-app-qmodem/Makefile
index cda50e2..6ba1bda 100644
--- a/luci/luci-app-qmodem/Makefile
+++ b/luci/luci-app-qmodem/Makefile
@@ -6,7 +6,7 @@ include $(TOPDIR)/rules.mk
 PKG_NAME:=luci-app-qmodem
 LUCI_TITLE:=LuCI support for QWRT Modem
 LUCI_PKGARCH:=all
-PKG_VERSION:=2.8.0
+PKG_VERSION:=2.8.1
 PKG_LICENSE:=GPLv3
 PKG_LINCESE_FILES:=LICENSE
 PKG_MAINTAINER:=Tom <fjrcn@outlook.com>
diff --git a/luci/luci-app-qmodem/root/usr/share/qmodem/modem_scan.sh b/luci/luci-app-qmodem/root/usr/share/qmodem/modem_scan.sh
index 2870060..4374a14 100755
--- a/luci/luci-app-qmodem/root/usr/share/qmodem/modem_scan.sh
+++ b/luci/luci-app-qmodem/root/usr/share/qmodem/modem_scan.sh
@@ -318,7 +318,7 @@ validate_at_port()
         [ ! -e "$dev_path" ] && continue
         res=$(fastat $dev_path "ATI")
         [ -z "$res" ] && continue
-        [[ "$res" != *"OK"* ]] && continue
+        !(echo "$res" | grep -qE 'OK') && continue
         valid_at_port="$at_port"
         [ -z "$valid_at_ports" ] && valid_at_ports="$valid_at_port" || valid_at_ports="$valid_at_ports $valid_at_port"
     done