diff --git a/app/services/experiments/move_to_project_service.rb b/app/services/experiments/move_to_project_service.rb
index fc48a2bfd..4b0bcfc6d 100644
--- a/app/services/experiments/move_to_project_service.rb
+++ b/app/services/experiments/move_to_project_service.rb
@@ -97,6 +97,7 @@ module Experiments
 
       child_associations.each do |child_association|
         [subject.public_send(child_association)].flatten.each do |child_subject|
+          next unless child_subject
           move_activities!(child_subject)
         end
       end