diff --git a/src/main/java/eu/siacs/conversations/persistance/DatabaseBackend.java b/src/main/java/eu/siacs/conversations/persistance/DatabaseBackend.java
index d9feabbe..b05044a0 100644
--- a/src/main/java/eu/siacs/conversations/persistance/DatabaseBackend.java
+++ b/src/main/java/eu/siacs/conversations/persistance/DatabaseBackend.java
@@ -58,7 +58,7 @@ public class DatabaseBackend extends SQLiteOpenHelper {
 	private static DatabaseBackend instance = null;
 
 	private static final String DATABASE_NAME = "history";
-	private static final int DATABASE_VERSION = 34;
+	private static final int DATABASE_VERSION = 35;
 
 	private static String CREATE_CONTATCS_STATEMENT = "create table "
 			+ Contact.TABLENAME + "(" + Contact.ACCOUNT + " TEXT, "
@@ -150,6 +150,7 @@ public class DatabaseBackend extends SQLiteOpenHelper {
 	private static String CREATE_START_TIMES_TABLE = "create table "+START_TIMES_TABLE+" (timestamp NUMBER);";
 
 	private static String CREATE_MESSAGE_TIME_INDEX = "create INDEX message_time_index ON "+Message.TABLENAME+"("+Message.TIME_SENT+")";
+	private static String CREATE_MESSAGE_CONVERSATION_INDEX = "create INDEX message_conversation_index ON "+Message.TABLENAME+"("+Message.CONVERSATION+")";
 
 	private DatabaseBackend(Context context) {
 		super(context, DATABASE_NAME, null, DATABASE_VERSION);
@@ -199,6 +200,7 @@ public class DatabaseBackend extends SQLiteOpenHelper {
 				+ Conversation.TABLENAME + "(" + Conversation.UUID
 				+ ") ON DELETE CASCADE);");
 		db.execSQL(CREATE_MESSAGE_TIME_INDEX);
+		db.execSQL(CREATE_MESSAGE_CONVERSATION_INDEX);
 		db.execSQL(CREATE_CONTATCS_STATEMENT);
 		db.execSQL(CREATE_DISCOVERY_RESULTS_STATEMENT);
 		db.execSQL(CREATE_SESSIONS_STATEMENT);
@@ -436,6 +438,9 @@ public class DatabaseBackend extends SQLiteOpenHelper {
 				}
 			}
 		}
+		if (oldVersion < 35 && newVersion >= 35) {
+			db.execSQL(CREATE_MESSAGE_CONVERSATION_INDEX);
+		}
 	}
 
 	private static ContentValues createFingerprintStatusContentValues(FingerprintStatus.Trust trust, boolean active) {