diff --git a/lib/tasks/data.rake b/lib/tasks/data.rake
new file mode 100644
index 00000000..215a1efe
--- /dev/null
+++ b/lib/tasks/data.rake
@@ -0,0 +1,29 @@
+namespace :data do
+  desc 'Nullify wrong foreign keys'
+
+  task nullify_nonexistent_foreign_keys: :environment do
+    # Track
+    events_track = Event.all.select { |e| e.track_id && Track.find_by(id: e.track_id).nil? }
+    nullify_attribute(events_track, 'track_id')
+
+    # Difficulty level
+    events_difficulty_level = Event.all.select { |e| e.difficulty_level_id && DifficultyLevel.find_by(id: e.difficulty_level_id).nil? }
+    nullify_attribute(events_difficulty_level, 'difficulty_level_id')
+
+    # Room
+    events_room = Event.all.select { |e| e.room_id && Room.find_by(id: e.room_id).nil? }
+    nullify_attribute(events_room, 'room_id')
+  end
+
+  def nullify_attribute(collection, attribute)
+    puts "Will nullify #{attribute} in #{ActionController::Base.helpers.pluralize(collection.length, 'event')}."
+    if collection.any?
+      puts "IDs: #{collection.map(&:id)}"
+      collection.each do |item|
+        item.send(attribute+'=', nil)
+        item.save!
+      end
+      puts "Fixed #{attribute}!"
+    end
+  end
+end