diff --git a/src/Proto.Actor/Mailbox/BatchingMailbox.cs b/src/Proto.Actor/Mailbox/BatchingMailbox.cs
index ba23070d27..8367d650e2 100644
--- a/src/Proto.Actor/Mailbox/BatchingMailbox.cs
+++ b/src/Proto.Actor/Mailbox/BatchingMailbox.cs
@@ -79,8 +79,8 @@ private async Task RunAsync()
             {
                 batch.Clear();
 
-                while ((msg = _userMessages.Pop()) is not null ||
-                       batch.Count >= _batchSize)
+                while (batch.Count < _batchSize &&
+                    (msg = _userMessages.Pop()) is not null)
                 {
                     batch.Add(msg!);
                 }