diff --git a/test/common.js b/test/common.js
index b35116d9..12bf426e 100644
--- a/test/common.js
+++ b/test/common.js
@@ -33,3 +33,25 @@ export function testRoundTripJsonSerialisable(Class, tests) {
 		}
 	}
 }
+
+
+/**
+ * Mark that this test takes a lot of time, or depends on a test that takes a
+ * lot of time.
+ */
+export function slowTest(test) {
+	if (process.env.FAST_TEST) {
+		test.skip();
+	}
+	test.timeout(30000);
+}
+
+/**
+ * Mark that this test depends on an external API and may be slow or flaky.
+ */
+export function externalTest(test) {
+	if (process.env.NO_EXTERNAL_TEST) {
+		test.skip();
+	}
+	test.timeout(60000);
+}
diff --git a/test/host/server.js b/test/host/server.js
index b3469fce..dd4789dc 100644
--- a/test/host/server.js
+++ b/test/host/server.js
@@ -6,7 +6,7 @@ import path from "node:path";
 import * as hostServer from "@clusterio/host/dist/node/src/server.js";
 import { Link, wait } from "@clusterio/lib";
 import { testLines } from "../lib/factorio/lines.js";
-import { slowTest, externalTest } from "../integration/index.js";
+import { slowTest, externalTest } from "../common.js";
 import "../setup_logging.js";
 
 
diff --git a/test/integration/clusterio.js b/test/integration/clusterio.js
index b68f3809..01cd0681 100644
--- a/test/integration/clusterio.js
+++ b/test/integration/clusterio.js
@@ -10,11 +10,12 @@ import * as libBuildMod from "@clusterio/lib/build_mod.js";
 
 import * as testStrings from "../lib/factorio/test_strings.js";
 import {
-	TestControl, TestControlConnector, url, controlToken, slowTest,
+	TestControl, TestControlConnector, url, controlToken,
 	execCtl, execCtlProcess, execController, execHost, sendRcon, getControl,
 	spawnNode, instancesDir, factorioDir, databaseDir, controllerConfigPath,
 	requiresFactorio, hasFactorio,
 } from "./index.js";
+import { slowTest } from "../common.js";
 import { ControllerEcho, HostEchoReceived } from "../file/test_plugin/messages.js";
 
 
diff --git a/test/integration/index.js b/test/integration/index.js
index 11db0d8e..48b018df 100644
--- a/test/integration/index.js
+++ b/test/integration/index.js
@@ -119,25 +119,6 @@ export class TestHostConnector extends lib.WebSocketClientConnector {
 	}
 }
 
-// Mark that this test takes a lot of time, or depends on a test that takes a lot of time.
-export function slowTest(test) {
-
-	if (process.env.FAST_TEST) {
-		test.skip();
-	}
-
-	test.timeout(30000);
-}
-
-// Mark that this test depends on an external API and may be slow or flaky.
-export function externalTest(test) {
-	if (process.env.NO_EXTERNAL_TEST) {
-		test.skip();
-	}
-
-	test.timeout(60000);
-}
-
 // Mark that this test or suite of tests requires a factorio install to run.
 export function requiresFactorio(testOrSuite) {
 	if (testOrSuite.skip) {
diff --git a/test/integration/instance.js b/test/integration/instance.js
index 8bcdec7d..e82d3bfb 100644
--- a/test/integration/instance.js
+++ b/test/integration/instance.js
@@ -3,9 +3,9 @@ import assert from "node:assert/strict";
 import * as lib from "@clusterio/lib";
 import fs from "node:fs/promises";
 
-import { testMatrix } from "../common.js";
+import { slowTest, testMatrix } from "../common.js";
 import {
-	slowTest, exec, execCtl, execCtlProcess, sendRcon, getControl,
+	execCtl, execCtlProcess, sendRcon, getControl,
 	requiresFactorio, hasFactorio, instancesDir,
 } from "./index.js";
 
diff --git a/test/integration/link.js b/test/integration/link.js
index 53b3c76b..8bfdd211 100644
--- a/test/integration/link.js
+++ b/test/integration/link.js
@@ -3,9 +3,10 @@ import events from "node:events";
 import jwt from "jsonwebtoken";
 
 import {
-	TestControlConnector, TestHostConnector, TestControl, get, exec, url, controlToken, slowTest,
+	TestControlConnector, TestHostConnector, TestControl, url, controlToken,
 } from "./index.js";
 import { ConnectionClosed, ProtocolError, PolicyViolation, AuthenticationFailed } from "@clusterio/lib";
+import { slowTest } from "../common.js";
 
 let tokenHost = jwt.sign({ aud: "host", host: 0 }, Buffer.from("TestSecretDoNotUse", "base64"));
 
diff --git a/test/integration/patch.js b/test/integration/patch.js
index d222ff6d..8f04302a 100644
--- a/test/integration/patch.js
+++ b/test/integration/patch.js
@@ -6,7 +6,7 @@ import path from "node:path";
 import { patch, SaveModule } from "@clusterio/host/dist/node/src/patch.js";
 import * as lib from "@clusterio/lib";
 
-import { slowTest } from "./index.js";
+import { slowTest } from "../common.js";
 
 
 // The server integration test is required to run before this one
diff --git a/test/integration/server.js b/test/integration/server.js
index f0e08c30..fe3d129b 100644
--- a/test/integration/server.js
+++ b/test/integration/server.js
@@ -8,7 +8,8 @@ import { InstanceManager } from "@clusterio/controller";
 import { FactorioServer, _getFactorioVersion } from "@clusterio/host/dist/node/src/server.js";
 import { logger } from "@clusterio/lib";
 
-import { slowTest, factorioDir, requiresFactorio } from "./index.js";
+import { factorioDir, requiresFactorio } from "./index.js";
+import { slowTest } from "../common.js";
 
 
 describe("Integration of host/src/server", function() {
diff --git a/test/lib/ModStore.test.js b/test/lib/ModStore.test.js
index cce56b59..4c7d1b0b 100644
--- a/test/lib/ModStore.test.js
+++ b/test/lib/ModStore.test.js
@@ -8,7 +8,7 @@ import JSZip from "jszip"; // Added for creating mock zips
 const nativeFetch = global.fetch;
 
 import { ModStore, ModInfo, ModVersionEquality } from "@clusterio/lib"; // Adjust path based on compiled output
-import { externalTest } from "../integration/index.js";
+import { externalTest } from "../common.js";
 import "../setup_logging.js";
 
 const MODS_DIR = path.join("temp", "test", "mod_store", "mods");
diff --git a/test/lib/external/FactorioVersions.test.js b/test/lib/external/FactorioVersions.test.js
index f63554d9..b87d9016 100644
--- a/test/lib/external/FactorioVersions.test.js
+++ b/test/lib/external/FactorioVersions.test.js
@@ -2,7 +2,7 @@ import assert from "node:assert/strict";
 import { readFile } from "node:fs/promises";
 
 import { fetchFactorioVersions } from "@clusterio/lib";
-import { slowTest, externalTest } from "../../integration/index.js";
+import { slowTest, externalTest } from "../../common.js";
 
 describe("FactorioVersions", function() {
 	describe("fetchFactorioVersions", function() {
diff --git a/test/lib/external/LatestReleases.test.js b/test/lib/external/LatestReleases.test.js
index 686b6b52..951e9376 100644
--- a/test/lib/external/LatestReleases.test.js
+++ b/test/lib/external/LatestReleases.test.js
@@ -1,7 +1,7 @@
 import assert from "node:assert/strict";
 
 import { fetchLatestReleases, resolveReleaseChannel } from "@clusterio/lib";
-import { slowTest, externalTest } from "../../integration/index.js";
+import { slowTest, externalTest } from "../../common.js";
 
 describe("LatestReleases", function() {
 	describe("fetchLatestReleases", function() {
diff --git a/test/lib/shared_commands.js b/test/lib/shared_commands.js
index d8c7dcc8..740550ad 100644
--- a/test/lib/shared_commands.js
+++ b/test/lib/shared_commands.js
@@ -3,7 +3,7 @@ import fs from "node:fs/promises";
 import path from "node:path";
 
 import * as lib from "@clusterio/lib";
-import { slowTest } from "../integration/index.js";
+import { slowTest } from "../common.js";
 import "../setup_logging.js";
 
 
diff --git a/test/messages/mod.test.js b/test/messages/mod.test.js
index 7371665b..486a6a2a 100644
--- a/test/messages/mod.test.js
+++ b/test/messages/mod.test.js
@@ -2,11 +2,9 @@ import assert from "node:assert/strict";
 
 import * as lib from "@clusterio/lib";
 import { ModDependencyResolveRequest, ModDependency, ModInfo } from "@clusterio/lib";
-
-import { testMatrix, testRoundTripJsonSerialisable } from "../common.js";
-
 import { Controller, ControlConnection } from "@clusterio/controller";
-import { externalTest } from "../integration/index.js";
+
+import { externalTest, testMatrix, testRoundTripJsonSerialisable } from "../common.js";
 import "../setup_logging.js";
 
 describe("messages/mod", function() {