diff --git a/bramble-core/src/main/java/org/briarproject/bramble/mailbox/MailboxApiImpl.java b/bramble-core/src/main/java/org/briarproject/bramble/mailbox/MailboxApiImpl.java
index 74012ae51..218283a42 100644
--- a/bramble-core/src/main/java/org/briarproject/bramble/mailbox/MailboxApiImpl.java
+++ b/bramble-core/src/main/java/org/briarproject/bramble/mailbox/MailboxApiImpl.java
@@ -108,7 +108,7 @@ class MailboxApiImpl implements MailboxApi {
 		OkHttpClient client = httpClientProvider.get();
 		Response response = client.newCall(request).execute();
 		if (response.code() == 409) throw new TolerableFailureException();
-		if (!response.isSuccessful()) throw new IOException();
+		if (!response.isSuccessful()) throw new ApiException();
 	}
 
 	private Request.Builder getRequestBuilder(String token) {
diff --git a/bramble-core/src/test/java/org/briarproject/bramble/mailbox/MailboxApiTest.java b/bramble-core/src/test/java/org/briarproject/bramble/mailbox/MailboxApiTest.java
index 5ab0bcbf2..5f4399ef3 100644
--- a/bramble-core/src/test/java/org/briarproject/bramble/mailbox/MailboxApiTest.java
+++ b/bramble-core/src/test/java/org/briarproject/bramble/mailbox/MailboxApiTest.java
@@ -9,8 +9,6 @@ import org.briarproject.bramble.mailbox.MailboxApi.TolerableFailureException;
 import org.briarproject.bramble.test.BrambleTestCase;
 import org.junit.Test;
 
-import java.io.IOException;
-
 import javax.annotation.Nonnull;
 import javax.net.SocketFactory;
 
@@ -200,7 +198,7 @@ public class MailboxApiTest extends BrambleTestCase {
 		assertEquals(expected, request1.getBody().readUtf8());
 
 		// request is not successful
-		assertThrows(IOException.class, () ->
+		assertThrows(ApiException.class, () ->
 				api.addContact(properties, mailboxContact));
 		RecordedRequest request2 = server.takeRequest();
 		assertEquals("/contacts", request2.getPath());