diff --git a/lib/subjects/remover.rb b/lib/subjects/remover.rb
index 456aae540..68262698d 100644
--- a/lib/subjects/remover.rb
+++ b/lib/subjects/remover.rb
@@ -60,7 +60,7 @@ def has_been_collected_or_classified?
     end
 
     def belongs_to_other_subject_set?
-      return false unless !subject_set_id.nil?
+      return false if subject_set_id.nil?
 
       orphan_subject.set_member_subjects.where.not(subject_set_id: subject_set_id).count.positive?
     end