diff --git a/Communication.md b/Communication.md
index ebf8a46..a89eb4d 100644
--- a/Communication.md
+++ b/Communication.md
@@ -172,7 +172,7 @@ Message JSON format is dictionary with keys:
 
 - **command** - type of progress. One of "STARTED" (evaluation started), "DOWNLOADED" (submission source downloaded), "TASK" (progress on one of the tasks), "UPLOADED" (results are uploaded), "ENDED" (evaluation ended)
 - **task_id** - id of currently evaluated task. Present only if **command** is "TASK".
-- **task_state** - state of task with id **task_id**. Present only if **command** is "TASK".
+- **task_state** - state of task with id **task_id**. Present only if **command** is "TASK". Value is one of "COMPLETED" and "FAILED".
 
 
 ## Frontend - Browser communication