diff --git a/briar-mailbox b/briar-mailbox
index d887c49ab..64147fd1d 160000
--- a/briar-mailbox
+++ b/briar-mailbox
@@ -1 +1 @@
-Subproject commit d887c49ab342d1d48d79e46fa6632852c4ab40b7
+Subproject commit 64147fd1d09764500c77948204c998aa6cfec347
diff --git a/mailbox-integration-tests/src/test/java/org/briarproject/bramble/mailbox/AbstractMailboxIntegrationTest.java b/mailbox-integration-tests/src/test/java/org/briarproject/bramble/mailbox/AbstractMailboxIntegrationTest.java
index ee1136a52..76c4770f9 100644
--- a/mailbox-integration-tests/src/test/java/org/briarproject/bramble/mailbox/AbstractMailboxIntegrationTest.java
+++ b/mailbox-integration-tests/src/test/java/org/briarproject/bramble/mailbox/AbstractMailboxIntegrationTest.java
@@ -29,6 +29,7 @@ import org.junit.Before;
 import java.io.File;
 import java.util.Map;
 import java.util.concurrent.CountDownLatch;
+import java.util.function.IntSupplier;
 
 import static java.util.concurrent.TimeUnit.SECONDS;
 import static org.briarproject.bramble.api.mailbox.MailboxAuthToken.fromString;
@@ -44,7 +45,7 @@ import static org.junit.Assert.fail;
 abstract class AbstractMailboxIntegrationTest
 		extends BrambleIntegrationTest<MailboxIntegrationTestComponent> {
 
-	static final String URL_BASE = "http://127.0.0.1:8000";
+	static final String URL_BASE = "http://127.0.0.1";
 
 	AbstractMailboxIntegrationTest() {
 		TestLogFormatter.use();
@@ -58,15 +59,16 @@ abstract class AbstractMailboxIntegrationTest
 	MailboxIntegrationTestComponent c1, c2;
 	Contact contact1From2, contact2From1;
 	TestMailbox mailbox;
-	MailboxApi api = createMailboxApi();
+	MailboxApi api;
 
 	@Before
 	@Override
 	public void setUp() throws Exception {
 		super.setUp();
-		c1 = startTestComponent(dir1, "Alice");
-		c2 = startTestComponent(dir2, "Bob");
 		mailbox = new TestMailbox(new File(testDir, "mailbox"));
+		c1 = startTestComponent(dir1, "Alice", () -> mailbox.getPort());
+		c2 = startTestComponent(dir2, "Bob", () -> mailbox.getPort());
+		api = createMailboxApi(() -> mailbox.getPort());
 		mailbox.startLifecycle();
 	}
 
@@ -82,16 +84,20 @@ abstract class AbstractMailboxIntegrationTest
 	}
 
 	private MailboxIntegrationTestComponent startTestComponent(
-			File databaseDir, String name) throws Exception {
+			File databaseDir, String name, IntSupplier portSupplier)
+			throws Exception {
 		TestThreadFactoryModule threadFactoryModule =
 				new TestThreadFactoryModule(name);
 		TestDatabaseConfigModule dbModule =
 				new TestDatabaseConfigModule(databaseDir);
+		TestModularMailboxModule mailboxModule =
+				new TestModularMailboxModule(portSupplier);
 		MailboxIntegrationTestComponent component =
 				DaggerMailboxIntegrationTestComponent
 						.builder()
 						.testThreadFactoryModule(threadFactoryModule)
 						.testDatabaseConfigModule(dbModule)
+						.testModularMailboxModule(mailboxModule)
 						.build();
 		injectEagerSingletons(component);
 
diff --git a/mailbox-integration-tests/src/test/java/org/briarproject/bramble/mailbox/MailboxApiIntegrationTest.java b/mailbox-integration-tests/src/test/java/org/briarproject/bramble/mailbox/MailboxApiIntegrationTest.java
index d196d180d..0c53bae99 100644
--- a/mailbox-integration-tests/src/test/java/org/briarproject/bramble/mailbox/MailboxApiIntegrationTest.java
+++ b/mailbox-integration-tests/src/test/java/org/briarproject/bramble/mailbox/MailboxApiIntegrationTest.java
@@ -49,7 +49,7 @@ public class MailboxApiIntegrationTest extends BrambleTestCase {
 	private TestMailbox mailbox;
 	private MailboxAuthToken setupToken;
 
-	private final MailboxApi api = createMailboxApi();
+	private MailboxApi api;
 
 	private MailboxProperties ownerProperties;
 
@@ -57,6 +57,7 @@ public class MailboxApiIntegrationTest extends BrambleTestCase {
 	public void setUp()
 			throws IOException, ApiException, InvalidMailboxIdException {
 		mailbox = new TestMailbox(dataDirectory.getRoot());
+		api = createMailboxApi(() -> mailbox.getPort());
 		mailbox.startLifecycle();
 
 		setupToken = MailboxAuthToken.fromString(mailbox.getSetupToken());
diff --git a/mailbox-integration-tests/src/test/java/org/briarproject/bramble/mailbox/MailboxIntegrationTestUtils.java b/mailbox-integration-tests/src/test/java/org/briarproject/bramble/mailbox/MailboxIntegrationTestUtils.java
index bcea13ea3..62b684605 100644
--- a/mailbox-integration-tests/src/test/java/org/briarproject/bramble/mailbox/MailboxIntegrationTestUtils.java
+++ b/mailbox-integration-tests/src/test/java/org/briarproject/bramble/mailbox/MailboxIntegrationTestUtils.java
@@ -1,15 +1,20 @@
 package org.briarproject.bramble.mailbox;
 
 import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.function.IntSupplier;
 
 import static java.lang.System.currentTimeMillis;
+import static org.briarproject.bramble.mailbox.AbstractMailboxIntegrationTest.URL_BASE;
 import static org.briarproject.bramble.mailbox.MailboxTestUtils.createHttpClientProvider;
-import static org.briarproject.bramble.mailbox.TestModularMailboxModule.urlConverter;
 import static org.junit.Assert.fail;
 
 class MailboxIntegrationTestUtils {
 
-	static MailboxApi createMailboxApi() {
+	static MailboxApi createMailboxApi(IntSupplier portSupplier) {
+		UrlConverter urlConverter = onion -> {
+			int port = portSupplier.getAsInt(); //only access when needed
+			return URL_BASE + ":" + port;
+		};
 		return new MailboxApiImpl(createHttpClientProvider(), urlConverter);
 	}
 
diff --git a/mailbox-integration-tests/src/test/java/org/briarproject/bramble/mailbox/OwnMailboxContactListWorkerIntegrationTest.java b/mailbox-integration-tests/src/test/java/org/briarproject/bramble/mailbox/OwnMailboxContactListWorkerIntegrationTest.java
index 40b12ffc5..7fb08d057 100644
--- a/mailbox-integration-tests/src/test/java/org/briarproject/bramble/mailbox/OwnMailboxContactListWorkerIntegrationTest.java
+++ b/mailbox-integration-tests/src/test/java/org/briarproject/bramble/mailbox/OwnMailboxContactListWorkerIntegrationTest.java
@@ -15,7 +15,6 @@ import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
 
-import static org.briarproject.bramble.mailbox.MailboxIntegrationTestUtils.createMailboxApi;
 import static org.briarproject.bramble.mailbox.MailboxIntegrationTestUtils.retryUntilSuccessOrTimeout;
 import static org.briarproject.bramble.test.TestUtils.getSecretKey;
 import static org.junit.Assert.assertEquals;
@@ -23,8 +22,6 @@ import static org.junit.Assert.assertEquals;
 public class OwnMailboxContactListWorkerIntegrationTest
 		extends AbstractMailboxIntegrationTest {
 
-	private final MailboxApi api = createMailboxApi();
-
 	private MailboxProperties ownerProperties;
 
 	private LocalAuthor localAuthor1;
diff --git a/mailbox-integration-tests/src/test/java/org/briarproject/bramble/mailbox/TestModularMailboxModule.java b/mailbox-integration-tests/src/test/java/org/briarproject/bramble/mailbox/TestModularMailboxModule.java
index 22e001bae..1284ceb3b 100644
--- a/mailbox-integration-tests/src/test/java/org/briarproject/bramble/mailbox/TestModularMailboxModule.java
+++ b/mailbox-integration-tests/src/test/java/org/briarproject/bramble/mailbox/TestModularMailboxModule.java
@@ -2,6 +2,8 @@ package org.briarproject.bramble.mailbox;
 
 import org.briarproject.nullsafety.NotNullByDefault;
 
+import java.util.function.IntSupplier;
+
 import dagger.Module;
 import dagger.Provides;
 
@@ -11,15 +13,22 @@ import static org.briarproject.bramble.mailbox.AbstractMailboxIntegrationTest.UR
 @NotNullByDefault
 class TestModularMailboxModule {
 
+	private final IntSupplier portSupplier;
+
+	TestModularMailboxModule(IntSupplier portSupplier) {
+		this.portSupplier = portSupplier;
+	}
+
 	@Provides
 	MailboxConfig provideMailboxConfig(TestMailboxConfigImpl mailboxConfig) {
 		return mailboxConfig;
 	}
 
-	static UrlConverter urlConverter = onion -> URL_BASE;
-
 	@Provides
 	UrlConverter provideUrlConverter() {
-		return urlConverter;
+		return onion -> {
+			int port = portSupplier.getAsInt();
+			return URL_BASE + ":" + port;
+		};
 	}
 }