diff --git a/roles/koschei/tasks/main.yml b/roles/koschei/tasks/main.yml
index 306787697d..b6535aaa42 100644
--- a/roles/koschei/tasks/main.yml
+++ b/roles/koschei/tasks/main.yml
@@ -168,3 +168,17 @@
   - restart koschei-resolver
   - restart koschei-scheduler
   - restart koschei-watcher
+
+- name: HOTFIX datetime error on unfinished tasks with finished parent
+  lineinfile: dest="/usr/lib/python2.7/site-packages/koschei/backend.py"
+              regexp="finished=datetime.fromtimestamp(task['completion_ts']),"
+              line="finished=datetime.fromtimestamp(task['completion_ts']) if task['completion_ts'] else None,"
+  when: env == "production"
+  tags:
+  - koschei
+  - hotfix
+  notify:
+  - restart koschei-polling
+  - restart koschei-resolver
+  - restart koschei-watcher
+  - restart koschei-scheduler