diff --git a/lib/encryption/olm_manager.dart b/lib/encryption/olm_manager.dart
index b08ab1b..d5b2fc1 100644
--- a/lib/encryption/olm_manager.dart
+++ b/lib/encryption/olm_manager.dart
@@ -23,6 +23,7 @@ import 'package:famedlysdk/famedlysdk.dart';
 import 'package:famedlysdk/matrix_api.dart';
 import 'package:olm/olm.dart' as olm;
 import './encryption.dart';
+import './utils/olm_session.dart';
 
 class OlmManager {
   final Encryption encryption;
@@ -43,8 +44,8 @@ class OlmManager {
   OlmManager(this.encryption);
 
   /// A map from Curve25519 identity keys to existing olm sessions.
-  Map<String, List<olm.Session>> get olmSessions => _olmSessions;
-  final Map<String, List<olm.Session>> _olmSessions = {};
+  Map<String, List<OlmSession>> get olmSessions => _olmSessions;
+  final Map<String, List<OlmSession>> _olmSessions = {};
 
   Future<void> init(String olmAccount) async {
     if (olmAccount == null) {
@@ -204,25 +205,24 @@ class OlmManager {
     }
   }
 
-  void storeOlmSession(String curve25519IdentityKey, olm.Session session) {
+  void storeOlmSession(OlmSession session) {
     if (client.database == null) {
       return;
     }
-    if (!_olmSessions.containsKey(curve25519IdentityKey)) {
-      _olmSessions[curve25519IdentityKey] = [];
+    if (!_olmSessions.containsKey(session.identityKey)) {
+      _olmSessions[session.identityKey] = [];
     }
-    final ix = _olmSessions[curve25519IdentityKey]
-        .indexWhere((s) => s.session_id() == session.session_id());
+    final ix = _olmSessions[session.identityKey]
+        .indexWhere((s) => s.sessionId == session.sessionId);
     if (ix == -1) {
       // add a new session
-      _olmSessions[curve25519IdentityKey].add(session);
+      _olmSessions[session.identityKey].add(session);
     } else {
       // update an existing session
-      _olmSessions[curve25519IdentityKey][ix] = session;
+      _olmSessions[session.identityKey][ix] = session;
     }
-    final pickle = session.pickle(client.userID);
-    client.database.storeOlmSession(
-        client.id, curve25519IdentityKey, session.session_id(), pickle);
+    client.database.storeOlmSession(client.id, session.identityKey,
+        session.sessionId, session.pickledSession, session.lastReceived);
   }
 
   ToDeviceEvent _decryptToDeviceEvent(ToDeviceEvent event) {
@@ -245,14 +245,16 @@ class OlmManager {
     var existingSessions = olmSessions[senderKey];
     if (existingSessions != null) {
       for (var session in existingSessions) {
-        if (type == 0 && session.matches_inbound(body) == true) {
-          plaintext = session.decrypt(type, body);
-          storeOlmSession(senderKey, session);
+        if (type == 0 && session.session.matches_inbound(body) == true) {
+          plaintext = session.session.decrypt(type, body);
+          session.lastReceived = DateTime.now();
+          storeOlmSession(session);
           break;
         } else if (type == 1) {
           try {
-            plaintext = session.decrypt(type, body);
-            storeOlmSession(senderKey, session);
+            plaintext = session.session.decrypt(type, body);
+            session.lastReceived = DateTime.now();
+            storeOlmSession(session);
             break;
           } catch (_) {
             plaintext = null;
@@ -271,7 +273,13 @@ class OlmManager {
         _olmAccount.remove_one_time_keys(newSession);
         client.database?.updateClientKeys(pickledOlmAccount, client.id);
         plaintext = newSession.decrypt(type, body);
-        storeOlmSession(senderKey, newSession);
+        storeOlmSession(OlmSession(
+          key: client.userID,
+          identityKey: identityKey,
+          sessionId: newSession.session_id(),
+          session: newSession,
+          lastReceived: DateTime.now(),
+        ));
       } catch (_) {
         newSession?.free();
         rethrow;
@@ -299,6 +307,22 @@ class OlmManager {
     );
   }
 
+  Future<List<OlmSession>> getOlmSessionsFromDatabase(String senderKey) async {
+    if (client.database == null) {
+      return [];
+    }
+    final rows =
+        await client.database.dbGetOlmSessions(client.id, senderKey).get();
+    final res = <OlmSession>[];
+    for (final row in rows) {
+      final sess = OlmSession.fromDb(row, client.userID);
+      if (sess.isValid) {
+        res.add(sess);
+      }
+    }
+    return res;
+  }
+
   Future<ToDeviceEvent> decryptToDeviceEvent(ToDeviceEvent event) async {
     if (event.type != EventTypes.Encrypted) {
       return event;
@@ -308,8 +332,7 @@ class OlmManager {
       if (client.database == null) {
         return false;
       }
-      final sessions = await client.database
-          .getSingleOlmSessions(client.id, senderKey, client.userID);
+      final sessions = await getOlmSessionsFromDatabase(senderKey);
       if (sessions.isEmpty) {
         return false; // okay, can't do anything
       }
@@ -352,11 +375,18 @@ class OlmManager {
               fingerprintKey, deviceKey, userId, deviceId)) {
             continue;
           }
+          var session = olm.Session();
           try {
-            var session = olm.Session();
             session.create_outbound(_olmAccount, identityKey, deviceKey['key']);
-            await storeOlmSession(identityKey, session);
+            await storeOlmSession(OlmSession(
+              key: client.userID,
+              identityKey: identityKey,
+              sessionId: session.session_id(),
+              session: session,
+              lastReceived: null,
+            ));
           } catch (e) {
+            session.free();
             print('[LibOlm] Could not create new outbound olm session: ' +
                 e.toString());
           }
@@ -369,14 +399,15 @@ class OlmManager {
       DeviceKeys device, String type, Map<String, dynamic> payload) async {
     var sess = olmSessions[device.curve25519Key];
     if (sess == null || sess.isEmpty) {
-      final sessions = await client.database
-          .getSingleOlmSessions(client.id, device.curve25519Key, client.userID);
+      final sessions = await getOlmSessionsFromDatabase(device.curve25519Key);
       if (sessions.isEmpty) {
         throw ('No olm session found');
       }
       sess = _olmSessions[device.curve25519Key] = sessions;
     }
-    sess.sort((a, b) => a.session_id().compareTo(b.session_id()));
+    sess.sort((a, b) => a.lastReceived == b.lastReceived
+        ? a.sessionId.compareTo(b.sessionId)
+        : b.lastReceived.compareTo(a.lastReceived));
     final fullPayload = {
       'type': type,
       'content': payload,
@@ -385,8 +416,8 @@ class OlmManager {
       'recipient': device.userId,
       'recipient_keys': {'ed25519': device.ed25519Key},
     };
-    final encryptResult = sess.first.encrypt(json.encode(fullPayload));
-    storeOlmSession(device.curve25519Key, sess.first);
+    final encryptResult = sess.first.session.encrypt(json.encode(fullPayload));
+    storeOlmSession(sess.first);
     final encryptedBody = <String, dynamic>{
       'algorithm': 'm.olm.v1.curve25519-aes-sha2',
       'sender_key': identityKey,
@@ -440,7 +471,7 @@ class OlmManager {
   void dispose() {
     for (final sessions in olmSessions.values) {
       for (final sess in sessions) {
-        sess.free();
+        sess.dispose();
       }
     }
     _olmAccount?.free();
diff --git a/lib/encryption/utils/olm_session.dart b/lib/encryption/utils/olm_session.dart
new file mode 100644
index 0000000..57e5655
--- /dev/null
+++ b/lib/encryption/utils/olm_session.dart
@@ -0,0 +1,59 @@
+/*
+ *   Famedly Matrix SDK
+ *   Copyright (C) 2020 Famedly GmbH
+ *
+ *   This program is free software: you can redistribute it and/or modify
+ *   it under the terms of the GNU Affero General Public License as
+ *   published by the Free Software Foundation, either version 3 of the
+ *   License, or (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ *   GNU Affero General Public License for more details.
+ *
+ *   You should have received a copy of the GNU Affero General Public License
+ *   along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+import 'package:olm/olm.dart' as olm;
+import '../../src/database/database.dart' show DbOlmSessions;
+
+class OlmSession {
+  String identityKey;
+  String sessionId;
+  olm.Session session;
+  DateTime lastReceived;
+  final String key;
+  String get pickledSession => session.pickle(key);
+
+  bool get isValid => session != null;
+
+  OlmSession({
+    this.key,
+    this.identityKey,
+    this.sessionId,
+    this.session,
+    this.lastReceived,
+  });
+
+  OlmSession.fromDb(DbOlmSessions dbEntry, String key) : key = key {
+    session = olm.Session();
+    try {
+      session.unpickle(key, dbEntry.pickle);
+      identityKey = dbEntry.identityKey;
+      sessionId = dbEntry.identityKey;
+      lastReceived =
+          dbEntry.lastReceived ?? DateTime.fromMillisecondsSinceEpoch(0);
+      assert(sessionId == session.session_id());
+    } catch (e) {
+      print('[LibOlm] Could not unpickle olm session: ' + e.toString());
+      dispose();
+    }
+  }
+
+  void dispose() {
+    session?.free();
+    session = null;
+  }
+}
diff --git a/lib/src/database/database.dart b/lib/src/database/database.dart
index 58ffac5..e19bb56 100644
--- a/lib/src/database/database.dart
+++ b/lib/src/database/database.dart
@@ -16,7 +16,7 @@ class Database extends _$Database {
   Database(QueryExecutor e) : super(e);
 
   @override
-  int get schemaVersion => 4;
+  int get schemaVersion => 5;
 
   int get maxFileSize => 1 * 1024 * 1024;
 
@@ -55,6 +55,10 @@ class Database extends _$Database {
                 'UPDATE user_device_keys SET outdated = true');
             from++;
           }
+          if (from == 4) {
+            await m.addColumn(olmSessions, olmSessions.lastReceived);
+            from++;
+          }
         },
         beforeOpen: (_) async {
           if (executor.dialect == SqlDialect.sqlite) {
@@ -114,22 +118,6 @@ class Database extends _$Database {
     return res;
   }
 
-  Future<List<olm.Session>> getSingleOlmSessions(
-      int clientId, String identityKey, String userId) async {
-    final rows = await dbGetOlmSessions(clientId, identityKey).get();
-    final res = <olm.Session>[];
-    for (final row in rows) {
-      try {
-        var session = olm.Session();
-        session.unpickle(userId, row.pickle);
-        res.add(session);
-      } catch (e) {
-        print('[LibOlm] Could not unpickle olm session: ' + e.toString());
-      }
-    }
-    return res;
-  }
-
   Future<DbOutboundGroupSession> getDbOutboundGroupSession(
       int clientId, String roomId) async {
     final res = await dbGetOutboundGroupSession(clientId, roomId).get();
diff --git a/lib/src/database/database.g.dart b/lib/src/database/database.g.dart
index 41485b6..d51eec5 100644
--- a/lib/src/database/database.g.dart
+++ b/lib/src/database/database.g.dart
@@ -1391,17 +1391,20 @@ class DbOlmSessions extends DataClass implements Insertable<DbOlmSessions> {
   final String identityKey;
   final String sessionId;
   final String pickle;
+  final DateTime lastReceived;
   DbOlmSessions(
       {@required this.clientId,
       @required this.identityKey,
       @required this.sessionId,
-      @required this.pickle});
+      @required this.pickle,
+      this.lastReceived});
   factory DbOlmSessions.fromData(
       Map<String, dynamic> data, GeneratedDatabase db,
       {String prefix}) {
     final effectivePrefix = prefix ?? '';
     final intType = db.typeSystem.forDartType<int>();
     final stringType = db.typeSystem.forDartType<String>();
+    final dateTimeType = db.typeSystem.forDartType<DateTime>();
     return DbOlmSessions(
       clientId:
           intType.mapFromDatabaseResponse(data['${effectivePrefix}client_id']),
@@ -1411,6 +1414,8 @@ class DbOlmSessions extends DataClass implements Insertable<DbOlmSessions> {
           .mapFromDatabaseResponse(data['${effectivePrefix}session_id']),
       pickle:
           stringType.mapFromDatabaseResponse(data['${effectivePrefix}pickle']),
+      lastReceived: dateTimeType
+          .mapFromDatabaseResponse(data['${effectivePrefix}last_received']),
     );
   }
   @override
@@ -1428,6 +1433,9 @@ class DbOlmSessions extends DataClass implements Insertable<DbOlmSessions> {
     if (!nullToAbsent || pickle != null) {
       map['pickle'] = Variable<String>(pickle);
     }
+    if (!nullToAbsent || lastReceived != null) {
+      map['last_received'] = Variable<DateTime>(lastReceived);
+    }
     return map;
   }
 
@@ -1439,6 +1447,7 @@ class DbOlmSessions extends DataClass implements Insertable<DbOlmSessions> {
       identityKey: serializer.fromJson<String>(json['identity_key']),
       sessionId: serializer.fromJson<String>(json['session_id']),
       pickle: serializer.fromJson<String>(json['pickle']),
+      lastReceived: serializer.fromJson<DateTime>(json['last_received']),
     );
   }
   @override
@@ -1449,6 +1458,7 @@ class DbOlmSessions extends DataClass implements Insertable<DbOlmSessions> {
       'identity_key': serializer.toJson<String>(identityKey),
       'session_id': serializer.toJson<String>(sessionId),
       'pickle': serializer.toJson<String>(pickle),
+      'last_received': serializer.toJson<DateTime>(lastReceived),
     };
   }
 
@@ -1456,12 +1466,14 @@ class DbOlmSessions extends DataClass implements Insertable<DbOlmSessions> {
           {int clientId,
           String identityKey,
           String sessionId,
-          String pickle}) =>
+          String pickle,
+          DateTime lastReceived}) =>
       DbOlmSessions(
         clientId: clientId ?? this.clientId,
         identityKey: identityKey ?? this.identityKey,
         sessionId: sessionId ?? this.sessionId,
         pickle: pickle ?? this.pickle,
+        lastReceived: lastReceived ?? this.lastReceived,
       );
   @override
   String toString() {
@@ -1469,14 +1481,19 @@ class DbOlmSessions extends DataClass implements Insertable<DbOlmSessions> {
           ..write('clientId: $clientId, ')
           ..write('identityKey: $identityKey, ')
           ..write('sessionId: $sessionId, ')
-          ..write('pickle: $pickle')
+          ..write('pickle: $pickle, ')
+          ..write('lastReceived: $lastReceived')
           ..write(')'))
         .toString();
   }
 
   @override
-  int get hashCode => $mrjf($mrjc(clientId.hashCode,
-      $mrjc(identityKey.hashCode, $mrjc(sessionId.hashCode, pickle.hashCode))));
+  int get hashCode => $mrjf($mrjc(
+      clientId.hashCode,
+      $mrjc(
+          identityKey.hashCode,
+          $mrjc(sessionId.hashCode,
+              $mrjc(pickle.hashCode, lastReceived.hashCode)))));
   @override
   bool operator ==(dynamic other) =>
       identical(this, other) ||
@@ -1484,7 +1501,8 @@ class DbOlmSessions extends DataClass implements Insertable<DbOlmSessions> {
           other.clientId == this.clientId &&
           other.identityKey == this.identityKey &&
           other.sessionId == this.sessionId &&
-          other.pickle == this.pickle);
+          other.pickle == this.pickle &&
+          other.lastReceived == this.lastReceived);
 }
 
 class OlmSessionsCompanion extends UpdateCompanion<DbOlmSessions> {
@@ -1492,17 +1510,20 @@ class OlmSessionsCompanion extends UpdateCompanion<DbOlmSessions> {
   final Value<String> identityKey;
   final Value<String> sessionId;
   final Value<String> pickle;
+  final Value<DateTime> lastReceived;
   const OlmSessionsCompanion({
     this.clientId = const Value.absent(),
     this.identityKey = const Value.absent(),
     this.sessionId = const Value.absent(),
     this.pickle = const Value.absent(),
+    this.lastReceived = const Value.absent(),
   });
   OlmSessionsCompanion.insert({
     @required int clientId,
     @required String identityKey,
     @required String sessionId,
     @required String pickle,
+    this.lastReceived = const Value.absent(),
   })  : clientId = Value(clientId),
         identityKey = Value(identityKey),
         sessionId = Value(sessionId),
@@ -1512,12 +1533,14 @@ class OlmSessionsCompanion extends UpdateCompanion<DbOlmSessions> {
     Expression<String> identityKey,
     Expression<String> sessionId,
     Expression<String> pickle,
+    Expression<DateTime> lastReceived,
   }) {
     return RawValuesInsertable({
       if (clientId != null) 'client_id': clientId,
       if (identityKey != null) 'identity_key': identityKey,
       if (sessionId != null) 'session_id': sessionId,
       if (pickle != null) 'pickle': pickle,
+      if (lastReceived != null) 'last_received': lastReceived,
     });
   }
 
@@ -1525,12 +1548,14 @@ class OlmSessionsCompanion extends UpdateCompanion<DbOlmSessions> {
       {Value<int> clientId,
       Value<String> identityKey,
       Value<String> sessionId,
-      Value<String> pickle}) {
+      Value<String> pickle,
+      Value<DateTime> lastReceived}) {
     return OlmSessionsCompanion(
       clientId: clientId ?? this.clientId,
       identityKey: identityKey ?? this.identityKey,
       sessionId: sessionId ?? this.sessionId,
       pickle: pickle ?? this.pickle,
+      lastReceived: lastReceived ?? this.lastReceived,
     );
   }
 
@@ -1549,6 +1574,9 @@ class OlmSessionsCompanion extends UpdateCompanion<DbOlmSessions> {
     if (pickle.present) {
       map['pickle'] = Variable<String>(pickle.value);
     }
+    if (lastReceived.present) {
+      map['last_received'] = Variable<DateTime>(lastReceived.value);
+    }
     return map;
   }
 }
@@ -1591,9 +1619,19 @@ class OlmSessions extends Table with TableInfo<OlmSessions, DbOlmSessions> {
         $customConstraints: 'NOT NULL');
   }
 
+  final VerificationMeta _lastReceivedMeta =
+      const VerificationMeta('lastReceived');
+  GeneratedDateTimeColumn _lastReceived;
+  GeneratedDateTimeColumn get lastReceived =>
+      _lastReceived ??= _constructLastReceived();
+  GeneratedDateTimeColumn _constructLastReceived() {
+    return GeneratedDateTimeColumn('last_received', $tableName, true,
+        $customConstraints: '');
+  }
+
   @override
   List<GeneratedColumn> get $columns =>
-      [clientId, identityKey, sessionId, pickle];
+      [clientId, identityKey, sessionId, pickle, lastReceived];
   @override
   OlmSessions get asDslTable => this;
   @override
@@ -1631,6 +1669,12 @@ class OlmSessions extends Table with TableInfo<OlmSessions, DbOlmSessions> {
     } else if (isInserting) {
       context.missing(_pickleMeta);
     }
+    if (data.containsKey('last_received')) {
+      context.handle(
+          _lastReceivedMeta,
+          lastReceived.isAcceptableOrUnknown(
+              data['last_received'], _lastReceivedMeta));
+    }
     return context;
   }
 
@@ -5520,6 +5564,7 @@ abstract class _$Database extends GeneratedDatabase {
       identityKey: row.readString('identity_key'),
       sessionId: row.readString('session_id'),
       pickle: row.readString('pickle'),
+      lastReceived: row.readDateTime('last_received'),
     );
   }
 
@@ -5543,15 +5588,16 @@ abstract class _$Database extends GeneratedDatabase {
         }).map(_rowToDbOlmSessions);
   }
 
-  Future<int> storeOlmSession(
-      int client_id, String identitiy_key, String session_id, String pickle) {
+  Future<int> storeOlmSession(int client_id, String identitiy_key,
+      String session_id, String pickle, DateTime last_received) {
     return customInsert(
-      'INSERT OR REPLACE INTO olm_sessions (client_id, identity_key, session_id, pickle) VALUES (:client_id, :identitiy_key, :session_id, :pickle)',
+      'INSERT OR REPLACE INTO olm_sessions (client_id, identity_key, session_id, pickle, last_received) VALUES (:client_id, :identitiy_key, :session_id, :pickle, :last_received)',
       variables: [
         Variable.withInt(client_id),
         Variable.withString(identitiy_key),
         Variable.withString(session_id),
-        Variable.withString(pickle)
+        Variable.withString(pickle),
+        Variable.withDateTime(last_received)
       ],
       updates: {olmSessions},
     );
diff --git a/lib/src/database/database.moor b/lib/src/database/database.moor
index 49a108d..c2e5ff0 100644
--- a/lib/src/database/database.moor
+++ b/lib/src/database/database.moor
@@ -48,6 +48,7 @@ CREATE TABLE olm_sessions (
   identity_key TEXT NOT NULL,
   session_id TEXT NOT NULL,
   pickle TEXT NOT NULL,
+  last_received DATETIME,
   UNIQUE(client_id, identity_key, session_id)
 ) AS DbOlmSessions;
 CREATE INDEX olm_sessions_index ON olm_sessions(client_id);
@@ -177,7 +178,7 @@ getAllUserDeviceKeysKeys: SELECT * FROM user_device_keys_key WHERE client_id = :
 getAllUserCrossSigningKeys: SELECT * FROM user_cross_signing_keys WHERE client_id = :client_id;
 getAllOlmSessions: SELECT * FROM olm_sessions WHERE client_id = :client_id;
 dbGetOlmSessions: SELECT * FROM olm_sessions WHERE client_id = :client_id AND identity_key = :identity_key;
-storeOlmSession: INSERT OR REPLACE INTO olm_sessions (client_id, identity_key, session_id, pickle) VALUES (:client_id, :identitiy_key, :session_id, :pickle);
+storeOlmSession: INSERT OR REPLACE INTO olm_sessions (client_id, identity_key, session_id, pickle, last_received) VALUES (:client_id, :identitiy_key, :session_id, :pickle, :last_received);
 getAllOutboundGroupSessions: SELECT * FROM outbound_group_sessions WHERE client_id = :client_id;
 dbGetOutboundGroupSession: SELECT * FROM outbound_group_sessions WHERE client_id = :client_id AND room_id = :room_id;
 storeOutboundGroupSession: INSERT OR REPLACE INTO outbound_group_sessions (client_id, room_id, pickle, device_ids, creation_time, sent_messages) VALUES (:client_id, :room_id, :pickle, :device_ids, :creation_time, :sent_messages);
diff --git a/test_driver/famedlysdk_test.dart b/test_driver/famedlysdk_test.dart
index 1dc8f9d..79cabfb 100644
--- a/test_driver/famedlysdk_test.dart
+++ b/test_driver/famedlysdk_test.dart
@@ -139,12 +139,10 @@ void test() async {
   assert(testClientB
           .encryption.olmManager.olmSessions[testClientA.identityKey].length ==
       1);
-  assert(testClientA
-          .encryption.olmManager.olmSessions[testClientB.identityKey].first
-          .session_id() ==
-      testClientB
-          .encryption.olmManager.olmSessions[testClientA.identityKey].first
-          .session_id());
+  assert(testClientA.encryption.olmManager.olmSessions[testClientB.identityKey]
+          .first.sessionId ==
+      testClientB.encryption.olmManager.olmSessions[testClientA.identityKey]
+          .first.sessionId);
   assert(inviteRoom.client.encryption.keyManager
           .getInboundGroupSession(inviteRoom.id, currentSessionIdA, '') !=
       null);
@@ -162,12 +160,10 @@ void test() async {
   assert(testClientB
           .encryption.olmManager.olmSessions[testClientA.identityKey].length ==
       1);
-  assert(testClientA
-          .encryption.olmManager.olmSessions[testClientB.identityKey].first
-          .session_id() ==
-      testClientB
-          .encryption.olmManager.olmSessions[testClientA.identityKey].first
-          .session_id());
+  assert(testClientA.encryption.olmManager.olmSessions[testClientB.identityKey]
+          .first.sessionId ==
+      testClientB.encryption.olmManager.olmSessions[testClientA.identityKey]
+          .first.sessionId);
 
   assert(room.client.encryption.keyManager
           .getOutboundGroupSession(room.id)
@@ -231,24 +227,20 @@ void test() async {
   assert(testClientB
           .encryption.olmManager.olmSessions[testClientA.identityKey].length ==
       1);
-  assert(testClientA
-          .encryption.olmManager.olmSessions[testClientB.identityKey].first
-          .session_id() ==
-      testClientB
-          .encryption.olmManager.olmSessions[testClientA.identityKey].first
-          .session_id());
+  assert(testClientA.encryption.olmManager.olmSessions[testClientB.identityKey]
+          .first.sessionId ==
+      testClientB.encryption.olmManager.olmSessions[testClientA.identityKey]
+          .first.sessionId);
   assert(testClientA
           .encryption.olmManager.olmSessions[testClientC.identityKey].length ==
       1);
   assert(testClientC
           .encryption.olmManager.olmSessions[testClientA.identityKey].length ==
       1);
-  assert(testClientA
-          .encryption.olmManager.olmSessions[testClientC.identityKey].first
-          .session_id() ==
-      testClientC
-          .encryption.olmManager.olmSessions[testClientA.identityKey].first
-          .session_id());
+  assert(testClientA.encryption.olmManager.olmSessions[testClientC.identityKey]
+          .first.sessionId ==
+      testClientC.encryption.olmManager.olmSessions[testClientA.identityKey]
+          .first.sessionId);
   assert(room.client.encryption.keyManager
           .getOutboundGroupSession(room.id)
           .outboundGroupSession
@@ -281,12 +273,10 @@ void test() async {
   assert(testClientB
           .encryption.olmManager.olmSessions[testClientA.identityKey].length ==
       1);
-  assert(testClientA
-          .encryption.olmManager.olmSessions[testClientB.identityKey].first
-          .session_id() ==
-      testClientB
-          .encryption.olmManager.olmSessions[testClientA.identityKey].first
-          .session_id());
+  assert(testClientA.encryption.olmManager.olmSessions[testClientB.identityKey]
+          .first.sessionId ==
+      testClientB.encryption.olmManager.olmSessions[testClientA.identityKey]
+          .first.sessionId);
   assert(room.client.encryption.keyManager
           .getOutboundGroupSession(room.id)
           .outboundGroupSession