diff --git a/bin/init-schools b/bin/init-schools
index 045b807338935b2bda2171f889b2a2f264f3bfd7..d176e5a179d3759356453e8b59d252e6342ef924 100755
--- a/bin/init-schools
+++ b/bin/init-schools
@@ -357,7 +357,8 @@ def plan_single_change(old: Optional[ProtoSchool], new: Optional[ProtoSchool]) -
             if getattr(old, field) != getattr(new, field):
                 changes.append((field, getattr(old, field), getattr(new, field)))
 
-        if set(changes) <= {'is_zs', 'is_ss'}:
+        changed_fields = {c[0] for c in changes}
+        if set(changed_fields) <= {'is_zs', 'is_ss'}:
             return None
 
         act = create_action(old, ActionType.EDIT, 'změny')