diff --git a/lib/src/omemo/sessionmanager.dart b/lib/src/omemo/sessionmanager.dart
index 3e924e1..ce10a7d 100644
--- a/lib/src/omemo/sessionmanager.dart
+++ b/lib/src/omemo/sessionmanager.dart
@@ -415,7 +415,7 @@ class OmemoSessionManager {
 
     await _lock.synchronized(() async {
       // Get devices for jid
-      final devices = _deviceMap[jid]!;
+      final devices = _deviceMap[jid] ?? [];
 
       for (final deviceId in devices) {
         final ratchet = _ratchetMap[RatchetMapKey(jid, deviceId)]!;