diff --git a/omemo/backend/util.py b/omemo/backend/util.py
index 93a3317..08930c5 100644
--- a/omemo/backend/util.py
+++ b/omemo/backend/util.py
@@ -25,7 +25,7 @@ DEFAULT_PREKEY_AMOUNT = 100
 MIN_PREKEY_AMOUNT = 80
 SPK_ARCHIVE_TIME = 86400 * 15  # 15 Days
 SPK_CYCLE_TIME = 86400         # 24 Hours
-UNACKNOWLEDGED_COUNT = 300
+UNACKNOWLEDGED_COUNT = 2000
 
 
 class Trust(IntEnum):