diff --git a/packages/lib/config/classes.js b/packages/lib/config/classes.js
index 101b8037..1a2cca36 100644
--- a/packages/lib/config/classes.js
+++ b/packages/lib/config/classes.js
@@ -2,8 +2,8 @@
 "use strict";
 
 const events = require("events");
-const util = require("util");
 
+const isDeepStrictEqual = require("../is_deep_strict_equal");
 const { basicType } = require("@clusterio/lib/helpers");
 
 
@@ -415,7 +415,7 @@ class ConfigGroup {
 
 		let prev = this._fields.get(name);
 		this._fields.set(name, value);
-		if (this._config && !util.isDeepStrictEqual(value, prev)) {
+		if (this._config && !isDeepStrictEqual(value, prev)) {
 			this._config.emit("fieldChanged", this, name, prev);
 		}
 	}
@@ -452,7 +452,7 @@ class ConfigGroup {
 
 		updated[prop] = value;
 		this._fields.set(name, updated);
-		if (this._config && !util.isDeepStrictEqual(updated, prev)) {
+		if (this._config && !isDeepStrictEqual(updated, prev)) {
 			this._config.emit("fieldChanged", this, name, prev);
 		}
 	}
@@ -502,7 +502,7 @@ class ConfigGroup {
 
 			let prev = this._fields.get(name);
 			this._fields.set(name, value);
-			if (notify && this._config && !util.isDeepStrictEqual(value, prev)) {
+			if (notify && this._config && !isDeepStrictEqual(value, prev)) {
 				this._config.emit("fieldChanged", this, name, prev);
 			}
 		}
diff --git a/packages/lib/is_deep_strict_equal.js b/packages/lib/is_deep_strict_equal.js
new file mode 100644
index 00000000..2a66f443
--- /dev/null
+++ b/packages/lib/is_deep_strict_equal.js
@@ -0,0 +1,7 @@
+"use strict";
+// eslint-disable-next-line no-process-env
+if (process.env.APP_ENV === "browser") {
+	module.exports = require("fast-deep-equal/es6");
+} else {
+	module.exports = require("util").isDeepStrictEqual;
+}
diff --git a/packages/lib/link/connectors.js b/packages/lib/link/connectors.js
index b18f9844..d3f3fe1f 100644
--- a/packages/lib/link/connectors.js
+++ b/packages/lib/link/connectors.js
@@ -1,7 +1,7 @@
 // Connection adapters for Links
 "use strict";
 const events = require("events");
-const WebSocket = require("ws");
+const WebSocket = require("isomorphic-ws");
 
 const schema = require("@clusterio/lib/schema");
 const errors = require("@clusterio/lib/errors");
@@ -236,11 +236,17 @@ class WebSocketClientConnector extends WebSocketBaseConnector {
 		// Open WebSocket to master
 		console.log(`SOCKET | connecting to ${url}`);
 
-		this._socket = new WebSocket(url, {
-			// For now we do not verify TLS certificates since the default setup is
-			// to create a self-signed certificate.
-			rejectUnauthorized: false,
-		});
+		// eslint-disable-next-line no-process-env
+		if (process.env.APP_ENV === "browser") {
+			this._socket = new WebSocket(url);
+
+		} else {
+			this._socket = new WebSocket(url, {
+				// For now we do not verify TLS certificates since the default setup is
+				// to create a self-signed certificate.
+				rejectUnauthorized: false,
+			});
+		}
 
 		this._attachSocketHandlers();
 	}
@@ -277,11 +283,11 @@ class WebSocketClientConnector extends WebSocketBaseConnector {
 	}
 
 	_attachSocketHandlers() {
-		this._socket.on("close", (code, reason) => {
-			console.log(`SOCKET | Close (code: ${code}, reason: ${reason})`);
+		this._socket.onclose = event => {
+			console.log(`SOCKET | Close (code: ${event.code}, reason: ${event.reason})`);
 			// Authentication failed
-			if (code === 4003) {
-				this.emit("error", new errors.AuthenticationFailed(reason));
+			if (event.code === 4003) {
+				this.emit("error", new errors.AuthenticationFailed(event.reason));
 				this._state = "closing";
 			}
 
@@ -303,26 +309,20 @@ class WebSocketClientConnector extends WebSocketBaseConnector {
 			}
 
 			this.stopHeartbeat();
-		});
+		};
 
-		this._socket.on("error", err => {
+		this._socket.onerror = event => {
 			// It's assumed that close is always called by ws
-			console.error("SOCKET | Error:", err);
-		});
+			console.error("SOCKET | Error:", event);
+		};
 
-		this._socket.on("open", () => {
+		this._socket.onopen = () => {
 			console.log("SOCKET | Open");
-		});
-		this._socket.on("ping", data => {
-			console.log(`SOCKET | Ping (data: ${data}`);
-		});
-		this._socket.on("pong", data => {
-			console.log(`SOCKET | Pong (data: ${data}`);
-		});
+		};
 
 		// Handle messages
-		this._socket.on("message", data => {
-			let message = JSON.parse(data);
+		this._socket.onmessage = event => {
+			let message = JSON.parse(event.data);
 			if (this._state === "handshake") {
 				this._processHandshake(message);
 
@@ -341,7 +341,7 @@ class WebSocketClientConnector extends WebSocketBaseConnector {
 			} else {
 				throw new Error(`Received message in unexpected state ${this._state}`);
 			}
-		});
+		};
 	}
 
 	_processHandshake(message) {
diff --git a/packages/lib/package.json b/packages/lib/package.json
index 6936c27c..290ead6f 100644
--- a/packages/lib/package.json
+++ b/packages/lib/package.json
@@ -13,6 +13,7 @@
   "dependencies": {
     "fs-extra": "^8.1.0",
     "ini": "^1.3.5",
+    "isomorphic-ws": "^4.0.1",
     "jimp": "^0.12.1",
     "jsonwebtoken": "^8.2.1",
     "jszip": "^3.2.2",
diff --git a/test/mock.js b/test/mock.js
index 03e851f9..f24f8708 100644
--- a/test/mock.js
+++ b/test/mock.js
@@ -18,6 +18,23 @@ class MockSocket {
 		this.events.set(event, fn);
 	}
 
+	/* eslint-disable accessor-pairs */
+	set onclose(fn) {
+		this.on("close", (code, reason) => fn({ code, reason }));
+	}
+
+	set onerror(fn) {
+		this.on("error", fn);
+	}
+
+	set onopen(fn) {
+		this.on("open", fn);
+	}
+
+	set onmessage(fn) {
+		this.on("message", (data) => fn({ data }));
+	}
+
 	terminate() {
 		this.terminateCalled = true;
 	}