diff --git a/bramble-api/src/main/java/org/briarproject/bramble/api/mailbox/MailboxUpdate.java b/bramble-api/src/main/java/org/briarproject/bramble/api/mailbox/MailboxUpdate.java
index b8cdb646b..891a8e5a9 100644
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/mailbox/MailboxUpdate.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/mailbox/MailboxUpdate.java
@@ -9,23 +9,22 @@ import javax.annotation.concurrent.Immutable;
 @Immutable
 @NotNullByDefault
 public class MailboxUpdate {
-
-	boolean hasMailbox;
-	private List<MailboxVersion> clientSupports;
+	private final boolean hasMailbox;
+	private final List<MailboxVersion> clientSupports;
 
 	public MailboxUpdate(List<MailboxVersion> clientSupports) {
-		this.hasMailbox = false;
+		this(clientSupports, false);
+	}
+
+	MailboxUpdate(List<MailboxVersion> clientSupports, boolean hasMailbox) {
 		this.clientSupports = clientSupports;
+		this.hasMailbox = hasMailbox;
 	}
 
 	public List<MailboxVersion> getClientSupports() {
 		return clientSupports;
 	}
 
-	public void setClientSupports(List<MailboxVersion> clientSupports) {
-		this.clientSupports = clientSupports;
-	}
-
 	public boolean hasMailbox() {
 		return hasMailbox;
 	}
diff --git a/bramble-api/src/main/java/org/briarproject/bramble/api/mailbox/MailboxUpdateWithMailbox.java b/bramble-api/src/main/java/org/briarproject/bramble/api/mailbox/MailboxUpdateWithMailbox.java
index e84506dbd..5e3110afa 100644
--- a/bramble-api/src/main/java/org/briarproject/bramble/api/mailbox/MailboxUpdateWithMailbox.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/api/mailbox/MailboxUpdateWithMailbox.java
@@ -20,8 +20,7 @@ public class MailboxUpdateWithMailbox extends MailboxUpdate {
 			MailboxAuthToken authToken, MailboxFolderId inboxId,
 			MailboxFolderId outboxId
 	) {
-		super(clientSupports);
-		this.hasMailbox = true;
+		super(clientSupports, true);
 		this.serverSupports = serverSupports;
 		this.onion = onion;
 		this.authToken = authToken;
@@ -29,6 +28,12 @@ public class MailboxUpdateWithMailbox extends MailboxUpdate {
 		this.outboxId = outboxId;
 	}
 
+	public MailboxUpdateWithMailbox(MailboxUpdateWithMailbox o,
+			List<MailboxVersion> newClientSupports) {
+		this(newClientSupports, o.serverSupports, o.onion, o.authToken,
+				o.inboxId, o.outboxId);
+	}
+
 	public String getOnion() {
 		return onion;
 	}
diff --git a/bramble-core/src/main/java/org/briarproject/bramble/mailbox/MailboxUpdateManagerImpl.java b/bramble-core/src/main/java/org/briarproject/bramble/mailbox/MailboxUpdateManagerImpl.java
index b8f1a8219..7511e5598 100644
--- a/bramble-core/src/main/java/org/briarproject/bramble/mailbox/MailboxUpdateManagerImpl.java
+++ b/bramble-core/src/main/java/org/briarproject/bramble/mailbox/MailboxUpdateManagerImpl.java
@@ -87,9 +87,16 @@ class MailboxUpdateManagerImpl implements MailboxUpdateManager,
 			for (Contact c : db.getContacts(txn)) {
 				MailboxUpdate latest = getLocalUpdate(txn, c.getId());
 				if (!latest.getClientSupports().equals(CLIENT_SUPPORTS)) {
-					latest.setClientSupports(CLIENT_SUPPORTS);
+					MailboxUpdate updated;
+					if (latest.hasMailbox()) {
+						updated = new MailboxUpdateWithMailbox(
+								(MailboxUpdateWithMailbox) latest,
+								CLIENT_SUPPORTS);
+					} else {
+						updated = new MailboxUpdate(CLIENT_SUPPORTS);
+					}
 					Group g = getContactGroup(c);
-					storeMessageReplaceLatest(txn, g.getId(), latest);
+					storeMessageReplaceLatest(txn, g.getId(), updated);
 				}
 			}
 			return;