diff --git a/extension.js b/extension.js
index 67eb63b..094e1c2 100644
--- a/extension.js
+++ b/extension.js
@@ -1,222 +1,210 @@
-const Clutter = imports.gi.Clutter;
-const St = imports.gi.St;
-const Main = imports.ui.main;
-// const Tweener = imports.ui.tweener;
-const Gio = imports.gi.Gio;
-const GLib = imports.gi.GLib;
-const ByteArray = imports.byteArray;
-
-const ExtensionUtils = imports.misc.extensionUtils;
-const Me = ExtensionUtils.getCurrentExtension();
-
-const PREFS_SCHEMA = 'org.gnome.shell.extensions.simplenetspeed';
-const refreshTime = 3;
-
-let settings;
-let button, timeout;
-// let icon, iconDark;
-let ioSpeed;
+// @ts-ignore
+import Clutter from 'gi://Clutter'
+// @ts-ignore
+import St from 'gi://St';
+// @ts-ignore
+import Gio from 'gi://Gio'
+// @ts-ignore
+import GLib from 'gi://GLib'
+
+// @ts-ignore
+import {Extension} from 'resource:///org/gnome/shell/extensions/extension.js';
+// @ts-ignore
+import * as Main from 'resource:///org/gnome/shell/ui/main.js';
+
+const REFRESH_TIME = 3;
+
 let lastCount = 0, lastSpeed = 0, lastCountUp = 0;
-let mode; // 0: kbps 1: K/s 2: U:kbps D:kbps 3: U:K/s D:K/s 4: Total KB
-let fontmode;
 let resetNextCount = false, resetCount = 0;
 
-function byteArrayToString(bytes) {
-    if (global.TextDecoder) {
-        return new TextDecoder().decode(bytes);
+export default class SimpleNetSpeedExtension extends Extension{
+    enable() {
+        const PREFS_SCHEMA = 'org.gnome.shell.extensions.simplenetspeed';
+        // @ts-ignore
+        this._settings = this.getSettings(PREFS_SCHEMA);
+
+        // 0: kbps 1: K/s 2: U:kbps D:kbps 3: U:K/s D:K/s 4: Total KB
+        // default mode using bit (bps, kbps)
+        this.mode = this._settings.get_int('mode');
+        this.fontmode = this._settings.get_int('fontmode');
+        console.log(`SimpleNetSpeed.enable: mode ${this.mode}, fontmode ${this.fontmode}`);
+
+        this.button = new St.Bin({
+            style_class: 'panel-button',
+            reactive: true,
+            can_focus: true,
+            x_expand: true,
+            y_expand: false,
+            track_hover: true
+        });
+
+        // let icon, iconDark;
+        this.ioSpeed = new St.Label({
+            text: '---',
+            y_align: Clutter.ActorAlign.CENTER,
+            style_class: 'simplenetspeed-label'
+        });
+
+        this.button.set_child(this.chooseLabel());
+        this.button.connect('button-press-event', this.changeMode.bind(this));
+
+        Main.panel._rightBox.insert_child_at_index(this.button, 0);
+        this.timeout = GLib.timeout_add_seconds(GLib.PRIORITY_DEFAULT, REFRESH_TIME, () => {
+            return this.parseStat();
+        });
     }
 
-    return imports.byteArray.toString(bytes);
-}
-
-function init() {
-
-}
-
-function changeMode(widget, event) {
-    // log(event.get_button());
-    if (event.get_button() == 3 && mode == 4) { // right click: reset downloaded sum
-        resetNextCount = true;
-        parseStat();
-    }
-    else if (event.get_button() == 2) { // change font
-        fontmode++;
-        if (fontmode > 4) {
-            fontmode=0;
+    disable() {
+        if (this.timeout) {
+            GLib.source_remove(this.timeout);
+            this.timeout = null;
         }
-        settings.set_int('fontmode', fontmode);
-        chooseLabel();
-        parseStat();
+        Main.panel._rightBox.remove_child(this.button);
+        this.button.destroy();
+        this.ioSpeed = null;
+        this.button = null;
+        this._settings = null;
     }
-    else if (event.get_button() == 1) {
-        mode++;
-        if (mode > 4) {
-            mode = 0;
+
+    changeMode(_widget, event) {
+        console.log('SimpleNetSpeed.changeMode, event button:' + event.get_button());
+        if (event.get_button() === 3 && this.mode === 4) { // right click: reset downloaded sum
+            resetNextCount = true;
+            this.parseStat();
+        }
+        else if (event.get_button() === 2) { // change font
+            this.fontmode++;
+            if (this.fontmode > 4) {
+                this.fontmode = 0;
+            }
+            this._settings.set_int('fontmode', this.fontmode);
+            this.chooseLabel();
+            this.parseStat();
+        }
+        else if (event.get_button() === 1) {
+            this.mode++;
+            if (this.mode > 4) {
+                this.mode = 0;
+            }
+            this._settings.set_int('mode', this.mode);
+            this.chooseLabel();
+            this.parseStat();
         }
-        settings.set_int('mode', mode);
-        chooseLabel();
-        parseStat();
+        console.log('SimpleNetSpeed.changeMode mode: ' + this.mode + ' font: ' + this.fontmode);
     }
-    log('mode:' + mode + ' font:' + fontmode);
-}
 
-function chooseLabel() {
-    if (mode == 0 || mode == 1 || mode == 4) {
-        styleName = 'simplenetspeed-label';
-    }
-    else { // 2 , 3
-        styleName = 'simplenetspeed-label-w';
-    }
+    chooseLabel() {
+        let styleName;
+        if (this.mode === 0 || this.mode === 1 || this.mode === 4) {
+            styleName = 'simplenetspeed-label';
+        }
+        else { // 2 , 3
+            styleName = 'simplenetspeed-label-w';
+        }
 
-    if (fontmode > 0) {
-        styleName = styleName + '-' + fontmode;
-    }
+        if (this.fontmode > 0) {
+            styleName = styleName + '-' + this.fontmode;
+        }
 
-    ioSpeed.set_style_class_name(styleName);
-    return ioSpeed;
-}
+        this.ioSpeed.set_style_class_name(styleName);
+        return this.ioSpeed;
+    }
 
-function parseStat() {
-    try {
-        let input_file = Gio.file_new_for_path('/proc/net/dev');
-
-        let [, contents, etag] = input_file.load_contents(null);
-        contents = byteArrayToString(contents);
-        let lines = contents.split('\n');
-
-        let count = 0;
-        let countUp = 0;
-        let line;
-
-        for (let i=0;i<lines.length;i++) {
-            line = lines[i];
-            line = line.trim();
-            let fields = line.split(/\W+/);
-            if (fields.length<=2) break;
-
-            if (fields[0] != "lo" &&
-                !fields[0].match(/^ifb[0-9]+/) && // created by python-based bandwidth manager "traffictoll"
-                !fields[0].match(/^lxdbr[0-9]+/) && // created by lxd container manager
-                !fields[0].match(/^virbr[0-9]+/) &&
-                !fields[0].match(/^br[0-9]+/) &&
-                !fields[0].match(/^vnet[0-9]+/) &&
-                !fields[0].match(/^tun[0-9]+/) &&
-                !fields[0].match(/^tap[0-9]+/) &&
-                !isNaN(parseInt(fields[1]))) {
-                    count = count + parseInt(fields[1]) + parseInt(fields[9]);
-                    countUp = countUp + parseInt(fields[9]);
+    // eslint-disable-next-line complexity
+    parseStat() {
+        try {
+            const input_file = Gio.file_new_for_path('/proc/net/dev');
+            const [, contents] = input_file.load_contents(null);
+            const lines = new TextDecoder().decode(contents).split('\n');
+
+            let count = 0;
+            let countUp = 0;
+            for (const line of lines) {
+                const fields = line.trim().split(/\W+/);
+                if (fields.length <= 2) break;
+
+                if (fields[0] !== "lo" &&
+                    !fields[0].match(/^ifb[0-9]+/) && // created by python-based bandwidth manager "traffictoll"
+                    !fields[0].match(/^lxdbr[0-9]+/) && // created by lxd container manager
+                    !fields[0].match(/^virbr[0-9]+/) &&
+                    !fields[0].match(/^br[0-9]+/) &&
+                    !fields[0].match(/^vnet[0-9]+/) &&
+                    !fields[0].match(/^tun[0-9]+/) &&
+                    !fields[0].match(/^tap[0-9]+/) &&
+                    !isNaN(parseInt(fields[1], 10))) {
+                    count = count + parseInt(fields[1], 10) + parseInt(fields[9], 10);
+                    countUp = countUp + parseInt(fields[9], 10);
+                }
             }
-        }
 
-        if (lastCount === 0) lastCount = count;
-        if (lastCountUp === 0) lastCountUp = countUp;
+            if (lastCount === 0) lastCount = count;
+            if (lastCountUp === 0) lastCountUp = countUp;
 
-        let speed = (count - lastCount) / refreshTime;
-        let speedUp = (countUp - lastCountUp) / refreshTime;
+            let speed = (count - lastCount) / REFRESH_TIME;
+            let speedUp = (countUp - lastCountUp) / REFRESH_TIME;
 
-        // TEST
-        // lastSpeed = 199899999;
-        // speed= 1998999999;
-        // speedUp= 99899999;
+            // TEST
+            // lastSpeed = 199899999;
+            // speed= 1998999999;
+            // speedUp= 99899999;
 
-        let dot = "";
-        if (speed > lastSpeed) {
-            dot = "⇅";
-        }
+            const dot = speed > lastSpeed ? "⇅" : "";
 
-        if (mode >= 0 && mode <= 1) {
-            ioSpeed.set_text(dot + speedToString(speed));
-        }
-        else if (mode >= 2 && mode <= 3) {
-            ioSpeed.set_text("↓" + speedToString(speed - speedUp) + " ↑" + speedToString(speedUp));
-        }
-        else if (mode == 4) {
-            if (resetNextCount == true) {
-                resetNextCount = false;
-                resetCount = count;
+            if (this.mode >= 0 && this.mode <= 1) {
+                this.ioSpeed.set_text(dot + this.speedToString(speed));
             }
-            ioSpeed.set_text("∑ " + speedToString(count - resetCount));
+            else if (this.mode >= 2 && this.mode <= 3) {
+                this.ioSpeed.set_text("↓" + this.speedToString(speed - speedUp) + " ↑" + this.speedToString(speedUp));
+            }
+            else if (this.mode === 4) {
+                if (resetNextCount === true) {
+                    resetNextCount = false;
+                    resetCount = count;
+                }
+                this.ioSpeed.set_text("∑ " + this.speedToString(count - resetCount));
+            }
+
+            lastCount = count;
+            lastCountUp = countUp;
+            lastSpeed = speed;
+        } catch (e) {
+            this.ioSpeed.set_text(e.message);
         }
 
-        lastCount = count;
-        lastCountUp = countUp;
-        lastSpeed = speed;
-    } catch (e) {
-        ioSpeed.set_text(e.message);
+        return GLib.SOURCE_CONTINUE;
     }
 
-    return GLib.SOURCE_CONTINUE;
-}
-
-function speedToString(amount) {
-    let digits;
-    let speed_map;
-    if (mode == 0 || mode == 2) {
-        speed_map = ["bps", "Kbps", "Mbps", "Gbps"];
-    }
-    else if (mode == 1 || mode == 3) {
-        speed_map = ["B/s", "K/s", "M/s", "G/s"];
-    }
-    else if (mode == 4) {
-        speed_map = ["B", "KB", "MB", "GB"];
-    }
+    speedToString(amount) {
+        let digits;
+        let speed_map = [];
+        if (this.mode === 0 || this.mode === 2) {
+            speed_map = ["bps", "Kbps", "Mbps", "Gbps"];
+        }
+        else if (this.mode === 1 || this.mode === 3) {
+            speed_map = ["B/s", "K/s", "M/s", "G/s"];
+        }
+        else if (this.mode === 4) {
+            speed_map = ["B", "KB", "MB", "GB"];
+        }
 
-    if (amount === 0)
-        return "0"  + speed_map[0];
+        if (amount === 0) {
+            return "0"  + speed_map[0];
+        }
 
-    if (mode==0 || mode==2) amount = amount * 8;
+        if (this.mode === 0 || this.mode === 2) amount = amount * 8;
 
-    let unit = 0;
-    while (amount >= 1000) { // 1M=1024K, 1MB/s=1000MB/s
-        amount /= 1000;
-        ++unit;
-    }
+        let unit = 0;
+        while (amount >= 1000) { // 1M=1024K, 1MB/s=1000MB/s
+            amount /= 1000;
+            ++unit;
+        }
 
-    if (amount >= 100) // 100MB 100KB 200KB
+        if (amount >= 100) // 100MB 100KB 200KB
         digits = 0;
-    else if (amount >= 10) // 10MB 10.2
+        else if (amount >= 10) // 10MB 10.2
         digits = 1;
-    else
+        else
         digits = 2;
-    return String(amount.toFixed(digits)) + speed_map[unit];
-}
-
-function enable() {
-    settings = ExtensionUtils.getSettings(PREFS_SCHEMA);
-
-    mode = settings.get_int('mode'); // default mode using bit (bps, kbps)
-    fontmode = settings.get_int('fontmode');
-
-    button = new St.Bin({
-        style_class: 'panel-button',
-        reactive: true,
-        can_focus: true,
-        x_expand: true,
-        y_expand: false,
-        track_hover: true
-    });
-
-    ioSpeed = new St.Label({
-        text: '---',
-        y_align: Clutter.ActorAlign.CENTER,
-        style_class: 'simplenetspeed-label'
-    });
-
-    button.set_child(chooseLabel());
-    button.connect('button-press-event', changeMode);
-
-    Main.panel._rightBox.insert_child_at_index(button, 0);
-    timeout = GLib.timeout_add_seconds(GLib.PRIORITY_DEFAULT, refreshTime, () => {
-        return parseStat();
-    });
-}
-
-function disable() {
-    if (timeout) {
-        GLib.source_remove(timeout);
-        timeout = null;
+        return String(amount.toFixed(digits)) + speed_map[unit];
     }
-    Main.panel._rightBox.remove_child(button);
-    button.destroy();
-    settings = button = ioSpeed = null;
 }
diff --git a/metadata.json b/metadata.json
index 1fd5d11..5ea9cb3 100644
--- a/metadata.json
+++ b/metadata.json
@@ -3,17 +3,9 @@
   "description": "Simply showing network speed. Left click to change modes:\n\n1. Total net speed in bits per second\n2. Total net speed in Bytes per second\n3. Up & down speed in bits per second\n4. Up & down speed in Bytes per second\n5. Total of downloaded in Bytes (Right click to reset counter)\n\nMiddle click to change font size",
   "name": "Simple net speed",
   "shell-version": [
-    "3.32",
-    "3.34",
-    "3.36",
-    "3.38",
-    "40",
-    "41",
-    "42",
-    "43",
-    "44"
+    "45"
   ],
   "url": "https://github.com/biji/simplenetspeed",
   "uuid": "simplenetspeed@biji.extension",
-  "version": 30
+  "version": 31
 }
diff --git a/schemas/gschemas.compiled b/schemas/gschemas.compiled
index e11bdb7..727b4e8 100644
Binary files a/schemas/gschemas.compiled and b/schemas/gschemas.compiled differ