diff --git a/hive/steem/block/stream.py b/hive/steem/block/stream.py
index 2b640bae13074d704b177c1d144583331bd9e33e..02bfe24a40d9b28695442574a23ebead4c5f6656 100644
--- a/hive/steem/block/stream.py
+++ b/hive/steem/block/stream.py
@@ -39,7 +39,7 @@ class BlockQueue:
             if self._queue: # if using max_size>0, fork might be in buffer only
                 buff = self.size()
                 alert = "NOTIFYALERT " if buff < self._max_size else ""
-                raise MicroForkException("%squeue:%d %s" % (alert, fork, buff))
+                raise MicroForkException("%squeue:%d %s" % (alert, buff, fork))
             raise ForkException("NOTIFYALERT fork " + fork)
 
         self._prev = next_hash