diff --git a/plugins/player_auth/test/plugin.js b/plugins/player_auth/test/plugin.js
index c63536e5..3ddc3ba6 100644
--- a/plugins/player_auth/test/plugin.js
+++ b/plugins/player_auth/test/plugin.js
@@ -7,9 +7,11 @@ const mock = require("../../../test/mock");
 const controller = require("../dist/node/controller");
 const instance = require("../dist/node/instance");
 const info = require("../dist/node/index").plugin;
-const { FetchPlayerCodeRequest, SetVerifyCodeRequest } = require("../dist/node/messages");
+const { FetchPlayerCodeRequest, SetVerifyCodeRequest, PlayerAuthServer } = require("../dist/node/messages");
+const { testRoundTripJsonSerialisable, testMatrix } = require("../../../test/common");
 const lib = require("@clusterio/lib");
 
+
 function postJSON(url, body) {
 	return fetch(url, {
 		method: "POST",
@@ -19,6 +21,44 @@ function postJSON(url, body) {
 }
 
 describe("player_auth", function() {
+	describe("messages.js", function() {
+		describe("PlayerAuthServer", function() {
+			it("should be round trip json serialisable", function() {
+				testRoundTripJsonSerialisable(PlayerAuthServer, testMatrix(
+					["server1", "server2"], // name
+					["127.0.0.1", "10.0.0.1:1234"], // address
+					[undefined, "1.1.0", "2.0.0"], // version
+				));
+			});
+		});
+
+		describe("FetchPlayerCodeResponse", function() {
+			it("should be round trip json serialisable", function() {
+				testRoundTripJsonSerialisable(FetchPlayerCodeRequest.Response, testMatrix(
+					["abc123", "player-code"], // playerCode
+					["http://localhost", "https://example.com"], // controllerUrl
+				));
+			});
+		});
+
+		describe("FetchPlayerCodeRequest", function() {
+			it("should be round trip json serialisable", function() {
+				testRoundTripJsonSerialisable(FetchPlayerCodeRequest, testMatrix(
+					["player1", "player2"], // player
+				));
+			});
+		});
+
+		describe("SetVerifyCodeRequest", function() {
+			it("should be round trip json serialisable", function() {
+				testRoundTripJsonSerialisable(SetVerifyCodeRequest, testMatrix(
+					["player1", "player2"], // player
+					["code123", "verify456"], // verifyCode
+				));
+			});
+		});
+	});
+
 	describe("controller.js", function() {
 		describe("generateCode()", function() {
 			it("should generate a code of the given length", async function() {
@@ -60,33 +100,46 @@ describe("player_auth", function() {
 
 			describe("/api/player_auth/servers", function() {
 				it("should return a list of running servers with player_auth loaded", async function() {
-					function addInstance(id, status, load, name) {
+					function addInstance(id, status, load, name, version) {
 						controllerPlugin.controller.instances.records.set(id, {
 							config: {
 								get(field) {
 									if (field === "player_auth.load_plugin") {
 										return load;
-									} else if (field === "factorio.settings") {
+									}
+									if (field === "factorio.settings") {
 										return { name };
-									} else if (field === "instance.id") {
+									}
+									if (field === "instance.id") {
 										return id;
 									}
+									if (field === "instance.assigned_host") {
+										return 1;
+									}
 									throw new Error(`field ${field} not implemented`);
 								},
 							},
 							status,
+							gamePort: 34197,
+							factorioVersion: version,
 						});
 					}
-					addInstance(1, "running", true, "running loaded");
-					addInstance(2, "stopped", true, "stopped loaded");
-					addInstance(3, "running", false, "running unloaded");
-					addInstance(4, "stopped", false, "stopped unloaded");
-					addInstance(5, "running", true, undefined);
+
+					addInstance(1, "running", true, "running loaded", "1.1.0");
+					addInstance(2, "stopped", true, "stopped loaded", "1.1.1");
+					addInstance(3, "running", false, "running unloaded", "1.1.2");
+					addInstance(4, "stopped", false, "stopped unloaded", "1.1.3");
+					addInstance(5, "running", true, undefined, undefined);
+
+					controllerPlugin.controller.hosts.set(1, {
+						publicAddress: "127.0.0.1",
+					});
+
 					const result = await fetch(`${controllerUrl}/api/player_auth/servers`);
-					assert.deepEqual(await result.json(), ["running loaded", "unnamed server"]);
-					for (let id of [1, 2, 3, 4, 5]) {
-						controllerPlugin.controller.instances.records.delete(id);
-					}
+					assert.deepEqual(await result.json(), [
+						{ name: "running loaded", address: "127.0.0.1:34197", factorioVersion: "1.1.0" },
+						{ name: "unnamed server", address: "127.0.0.1:34197" },
+					]);
 				});
 			});