diff --git a/briar-android/src/org/briarproject/android/contact/ContactListActivity.java b/briar-android/src/org/briarproject/android/contact/ContactListActivity.java
index 094de1133..02a244c23 100644
--- a/briar-android/src/org/briarproject/android/contact/ContactListActivity.java
+++ b/briar-android/src/org/briarproject/android/contact/ContactListActivity.java
@@ -28,7 +28,6 @@ import org.briarproject.api.Contact;
 import org.briarproject.api.ContactId;
 import org.briarproject.api.db.DatabaseComponent;
 import org.briarproject.api.db.DbException;
-import org.briarproject.api.db.MessageHeader;
 import org.briarproject.api.db.NoSuchContactException;
 import org.briarproject.api.event.ContactAddedEvent;
 import org.briarproject.api.event.ContactConnectedEvent;
@@ -41,6 +40,7 @@ import org.briarproject.api.event.MessageAddedEvent;
 import org.briarproject.api.event.MessageExpiredEvent;
 import org.briarproject.api.plugins.ConnectionRegistry;
 import org.briarproject.api.sync.GroupId;
+import org.briarproject.api.sync.MessageHeader;
 
 import java.util.Collection;
 import java.util.logging.Logger;
diff --git a/briar-android/src/org/briarproject/android/contact/ContactListItem.java b/briar-android/src/org/briarproject/android/contact/ContactListItem.java
index 19cec75cc..0e2cca813 100644
--- a/briar-android/src/org/briarproject/android/contact/ContactListItem.java
+++ b/briar-android/src/org/briarproject/android/contact/ContactListItem.java
@@ -1,8 +1,8 @@
 package org.briarproject.android.contact;
 
 import org.briarproject.api.Contact;
-import org.briarproject.api.db.MessageHeader;
 import org.briarproject.api.sync.GroupId;
+import org.briarproject.api.sync.MessageHeader;
 
 import java.util.Collection;
 
diff --git a/briar-android/src/org/briarproject/android/contact/ConversationActivity.java b/briar-android/src/org/briarproject/android/contact/ConversationActivity.java
index 76cc95310..017cbfa0d 100644
--- a/briar-android/src/org/briarproject/android/contact/ConversationActivity.java
+++ b/briar-android/src/org/briarproject/android/contact/ConversationActivity.java
@@ -27,8 +27,6 @@ import org.briarproject.api.android.AndroidNotificationManager;
 import org.briarproject.api.crypto.CryptoExecutor;
 import org.briarproject.api.db.DatabaseComponent;
 import org.briarproject.api.db.DbException;
-import org.briarproject.api.db.MessageHeader;
-import org.briarproject.api.db.MessageHeader.State;
 import org.briarproject.api.db.NoSuchContactException;
 import org.briarproject.api.db.NoSuchMessageException;
 import org.briarproject.api.db.NoSuchSubscriptionException;
@@ -44,6 +42,8 @@ import org.briarproject.api.sync.Group;
 import org.briarproject.api.sync.GroupId;
 import org.briarproject.api.sync.Message;
 import org.briarproject.api.sync.MessageFactory;
+import org.briarproject.api.sync.MessageHeader;
+import org.briarproject.api.sync.MessageHeader.State;
 import org.briarproject.api.sync.MessageId;
 import org.briarproject.util.StringUtils;
 
diff --git a/briar-android/src/org/briarproject/android/contact/ConversationAdapter.java b/briar-android/src/org/briarproject/android/contact/ConversationAdapter.java
index f78f4bb68..240bdea4d 100644
--- a/briar-android/src/org/briarproject/android/contact/ConversationAdapter.java
+++ b/briar-android/src/org/briarproject/android/contact/ConversationAdapter.java
@@ -1,21 +1,5 @@
 package org.briarproject.android.contact;
 
-import static android.view.Gravity.BOTTOM;
-import static android.view.Gravity.LEFT;
-import static android.view.View.INVISIBLE;
-import static android.widget.LinearLayout.HORIZONTAL;
-import static android.widget.LinearLayout.VERTICAL;
-import static org.briarproject.android.util.CommonLayoutParams.MATCH_WRAP;
-
-import java.util.ArrayList;
-
-import org.briarproject.R;
-import org.briarproject.android.util.ElasticHorizontalSpace;
-import org.briarproject.android.util.LayoutUtils;
-import org.briarproject.api.db.MessageHeader;
-import org.briarproject.api.db.MessageHeader.State;
-import org.briarproject.util.StringUtils;
-
 import android.content.Context;
 import android.content.res.Resources;
 import android.text.format.DateUtils;
@@ -27,6 +11,21 @@ import android.widget.ImageView;
 import android.widget.LinearLayout;
 import android.widget.TextView;
 
+import org.briarproject.R;
+import org.briarproject.android.util.ElasticHorizontalSpace;
+import org.briarproject.android.util.LayoutUtils;
+import org.briarproject.api.sync.MessageHeader;
+import org.briarproject.api.sync.MessageHeader.State;
+import org.briarproject.util.StringUtils;
+
+import java.util.ArrayList;
+
+import static android.view.Gravity.BOTTOM;
+import static android.view.Gravity.LEFT;
+import static android.widget.LinearLayout.HORIZONTAL;
+import static android.widget.LinearLayout.VERTICAL;
+import static org.briarproject.android.util.CommonLayoutParams.MATCH_WRAP;
+
 class ConversationAdapter extends ArrayAdapter<ConversationItem> {
 
 	private final int pad;
diff --git a/briar-android/src/org/briarproject/android/contact/ConversationItem.java b/briar-android/src/org/briarproject/android/contact/ConversationItem.java
index ac5637e16..292bd4a71 100644
--- a/briar-android/src/org/briarproject/android/contact/ConversationItem.java
+++ b/briar-android/src/org/briarproject/android/contact/ConversationItem.java
@@ -1,7 +1,7 @@
 package org.briarproject.android.contact;
 
-import org.briarproject.api.db.MessageHeader;
-import org.briarproject.api.db.MessageHeader.State;
+import org.briarproject.api.sync.MessageHeader;
+import org.briarproject.api.sync.MessageHeader.State;
 
 // This class is not thread-safe
 class ConversationItem {
diff --git a/briar-android/src/org/briarproject/android/forum/ForumActivity.java b/briar-android/src/org/briarproject/android/forum/ForumActivity.java
index e17719ece..3c4b5a267 100644
--- a/briar-android/src/org/briarproject/android/forum/ForumActivity.java
+++ b/briar-android/src/org/briarproject/android/forum/ForumActivity.java
@@ -21,7 +21,6 @@ import org.briarproject.api.Author;
 import org.briarproject.api.android.AndroidNotificationManager;
 import org.briarproject.api.db.DatabaseComponent;
 import org.briarproject.api.db.DbException;
-import org.briarproject.api.db.MessageHeader;
 import org.briarproject.api.db.NoSuchMessageException;
 import org.briarproject.api.db.NoSuchSubscriptionException;
 import org.briarproject.api.event.Event;
@@ -32,6 +31,7 @@ import org.briarproject.api.event.MessageExpiredEvent;
 import org.briarproject.api.event.SubscriptionRemovedEvent;
 import org.briarproject.api.sync.Group;
 import org.briarproject.api.sync.GroupId;
+import org.briarproject.api.sync.MessageHeader;
 import org.briarproject.api.sync.MessageId;
 
 import java.util.ArrayList;
diff --git a/briar-android/src/org/briarproject/android/forum/ForumAdapter.java b/briar-android/src/org/briarproject/android/forum/ForumAdapter.java
index cc8db894d..8660f4381 100644
--- a/briar-android/src/org/briarproject/android/forum/ForumAdapter.java
+++ b/briar-android/src/org/briarproject/android/forum/ForumAdapter.java
@@ -14,7 +14,7 @@ import org.briarproject.R;
 import org.briarproject.android.util.AuthorView;
 import org.briarproject.android.util.LayoutUtils;
 import org.briarproject.api.Author;
-import org.briarproject.api.db.MessageHeader;
+import org.briarproject.api.sync.MessageHeader;
 import org.briarproject.util.StringUtils;
 
 import java.util.ArrayList;
diff --git a/briar-android/src/org/briarproject/android/forum/ForumItem.java b/briar-android/src/org/briarproject/android/forum/ForumItem.java
index ca42d7e9a..ec87cbf03 100644
--- a/briar-android/src/org/briarproject/android/forum/ForumItem.java
+++ b/briar-android/src/org/briarproject/android/forum/ForumItem.java
@@ -1,6 +1,6 @@
 package org.briarproject.android.forum;
 
-import org.briarproject.api.db.MessageHeader;
+import org.briarproject.api.sync.MessageHeader;
 
 // This class is not thread-safe
 class ForumItem {
diff --git a/briar-android/src/org/briarproject/android/forum/ForumListActivity.java b/briar-android/src/org/briarproject/android/forum/ForumListActivity.java
index 1b061f44a..38f1d4356 100644
--- a/briar-android/src/org/briarproject/android/forum/ForumListActivity.java
+++ b/briar-android/src/org/briarproject/android/forum/ForumListActivity.java
@@ -25,7 +25,6 @@ import org.briarproject.android.util.LayoutUtils;
 import org.briarproject.android.util.ListLoadingProgressBar;
 import org.briarproject.api.db.DatabaseComponent;
 import org.briarproject.api.db.DbException;
-import org.briarproject.api.db.MessageHeader;
 import org.briarproject.api.db.NoSuchSubscriptionException;
 import org.briarproject.api.event.Event;
 import org.briarproject.api.event.EventBus;
@@ -37,6 +36,7 @@ import org.briarproject.api.event.SubscriptionAddedEvent;
 import org.briarproject.api.event.SubscriptionRemovedEvent;
 import org.briarproject.api.sync.Group;
 import org.briarproject.api.sync.GroupId;
+import org.briarproject.api.sync.MessageHeader;
 
 import java.util.Collection;
 import java.util.Map;
diff --git a/briar-android/src/org/briarproject/android/forum/ForumListItem.java b/briar-android/src/org/briarproject/android/forum/ForumListItem.java
index a41ae98f3..3eef6c436 100644
--- a/briar-android/src/org/briarproject/android/forum/ForumListItem.java
+++ b/briar-android/src/org/briarproject/android/forum/ForumListItem.java
@@ -1,7 +1,7 @@
 package org.briarproject.android.forum;
 
-import org.briarproject.api.db.MessageHeader;
 import org.briarproject.api.sync.Group;
+import org.briarproject.api.sync.MessageHeader;
 
 import java.util.Collection;
 
diff --git a/briar-api/src/org/briarproject/api/db/DatabaseComponent.java b/briar-api/src/org/briarproject/api/db/DatabaseComponent.java
index c76a155d9..9aff24206 100644
--- a/briar-api/src/org/briarproject/api/db/DatabaseComponent.java
+++ b/briar-api/src/org/briarproject/api/db/DatabaseComponent.java
@@ -179,7 +179,7 @@ public interface DatabaseComponent {
 	 * Returns the headers of all messages in the inbox group for the given
 	 * contact, or null if no inbox group has been set.
 	 */
-	Collection<MessageHeader> getInboxMessageHeaders(ContactId c)
+	Collection<org.briarproject.api.sync.MessageHeader> getInboxMessageHeaders(ContactId c)
 			throws DbException;
 
 	/** Returns the local pseudonym with the given ID. */
@@ -199,7 +199,7 @@ public interface DatabaseComponent {
 	byte[] getMessageBody(MessageId m) throws DbException;
 
 	/** Returns the headers of all messages in the given group. */
-	Collection<MessageHeader> getMessageHeaders(GroupId g)
+	Collection<org.briarproject.api.sync.MessageHeader> getMessageHeaders(GroupId g)
 			throws DbException;
 
 	/** Returns true if the given message is marked as read. */
diff --git a/briar-api/src/org/briarproject/api/db/MessageHeader.java b/briar-api/src/org/briarproject/api/sync/MessageHeader.java
similarity index 94%
rename from briar-api/src/org/briarproject/api/db/MessageHeader.java
rename to briar-api/src/org/briarproject/api/sync/MessageHeader.java
index 7ba4eaaf1..e70e1fef1 100644
--- a/briar-api/src/org/briarproject/api/db/MessageHeader.java
+++ b/briar-api/src/org/briarproject/api/sync/MessageHeader.java
@@ -1,8 +1,6 @@
-package org.briarproject.api.db;
+package org.briarproject.api.sync;
 
 import org.briarproject.api.Author;
-import org.briarproject.api.sync.GroupId;
-import org.briarproject.api.sync.MessageId;
 
 public class MessageHeader {
 
diff --git a/briar-core/src/org/briarproject/db/Database.java b/briar-core/src/org/briarproject/db/Database.java
index feeb4381b..9e0e8045c 100644
--- a/briar-core/src/org/briarproject/db/Database.java
+++ b/briar-core/src/org/briarproject/db/Database.java
@@ -10,10 +10,10 @@ import org.briarproject.api.TransportConfig;
 import org.briarproject.api.TransportId;
 import org.briarproject.api.TransportProperties;
 import org.briarproject.api.db.DbException;
-import org.briarproject.api.db.MessageHeader;
 import org.briarproject.api.sync.Group;
 import org.briarproject.api.sync.GroupId;
 import org.briarproject.api.sync.Message;
+import org.briarproject.api.sync.MessageHeader;
 import org.briarproject.api.sync.MessageId;
 import org.briarproject.api.sync.RetentionAck;
 import org.briarproject.api.sync.RetentionUpdate;
diff --git a/briar-core/src/org/briarproject/db/DatabaseComponentImpl.java b/briar-core/src/org/briarproject/db/DatabaseComponentImpl.java
index caa88847d..280dda05b 100644
--- a/briar-core/src/org/briarproject/db/DatabaseComponentImpl.java
+++ b/briar-core/src/org/briarproject/db/DatabaseComponentImpl.java
@@ -13,7 +13,6 @@ import org.briarproject.api.db.ContactExistsException;
 import org.briarproject.api.db.DatabaseComponent;
 import org.briarproject.api.db.DbException;
 import org.briarproject.api.db.LocalAuthorExistsException;
-import org.briarproject.api.db.MessageHeader;
 import org.briarproject.api.db.NoSuchContactException;
 import org.briarproject.api.db.NoSuchLocalAuthorException;
 import org.briarproject.api.db.NoSuchMessageException;
@@ -46,6 +45,7 @@ import org.briarproject.api.sync.Ack;
 import org.briarproject.api.sync.Group;
 import org.briarproject.api.sync.GroupId;
 import org.briarproject.api.sync.Message;
+import org.briarproject.api.sync.MessageHeader;
 import org.briarproject.api.sync.MessageId;
 import org.briarproject.api.sync.Offer;
 import org.briarproject.api.sync.Request;
diff --git a/briar-core/src/org/briarproject/db/JdbcDatabase.java b/briar-core/src/org/briarproject/db/JdbcDatabase.java
index f0dd8c532..f51f4e192 100644
--- a/briar-core/src/org/briarproject/db/JdbcDatabase.java
+++ b/briar-core/src/org/briarproject/db/JdbcDatabase.java
@@ -12,11 +12,11 @@ import org.briarproject.api.TransportProperties;
 import org.briarproject.api.crypto.SecretKey;
 import org.briarproject.api.db.DbClosedException;
 import org.briarproject.api.db.DbException;
-import org.briarproject.api.db.MessageHeader;
-import org.briarproject.api.db.MessageHeader.State;
 import org.briarproject.api.sync.Group;
 import org.briarproject.api.sync.GroupId;
 import org.briarproject.api.sync.Message;
+import org.briarproject.api.sync.MessageHeader;
+import org.briarproject.api.sync.MessageHeader.State;
 import org.briarproject.api.sync.MessageId;
 import org.briarproject.api.sync.RetentionAck;
 import org.briarproject.api.sync.RetentionUpdate;
diff --git a/briar-tests/src/org/briarproject/db/H2DatabaseTest.java b/briar-tests/src/org/briarproject/db/H2DatabaseTest.java
index 4c0b0b6e2..686789f68 100644
--- a/briar-tests/src/org/briarproject/db/H2DatabaseTest.java
+++ b/briar-tests/src/org/briarproject/db/H2DatabaseTest.java
@@ -13,10 +13,10 @@ import org.briarproject.api.TransportId;
 import org.briarproject.api.TransportProperties;
 import org.briarproject.api.crypto.SecretKey;
 import org.briarproject.api.db.DbException;
-import org.briarproject.api.db.MessageHeader;
 import org.briarproject.api.sync.Group;
 import org.briarproject.api.sync.GroupId;
 import org.briarproject.api.sync.Message;
+import org.briarproject.api.sync.MessageHeader;
 import org.briarproject.api.sync.MessageId;
 import org.briarproject.api.transport.IncomingKeys;
 import org.briarproject.api.transport.OutgoingKeys;
@@ -43,7 +43,7 @@ import java.util.concurrent.atomic.AtomicBoolean;
 
 import static java.util.concurrent.TimeUnit.SECONDS;
 import static org.briarproject.api.AuthorConstants.MAX_PUBLIC_KEY_LENGTH;
-import static org.briarproject.api.db.MessageHeader.State.STORED;
+import static org.briarproject.api.sync.MessageHeader.State.STORED;
 import static org.briarproject.api.sync.MessagingConstants.GROUP_SALT_LENGTH;
 import static org.junit.Assert.assertArrayEquals;
 import static org.junit.Assert.assertEquals;