diff --git a/app/models/student_works_score.rb b/app/models/student_works_score.rb
index 162ba59b4..19043f7f8 100644
--- a/app/models/student_works_score.rb
+++ b/app/models/student_works_score.rb
@@ -14,8 +14,7 @@ belongs_to :student_work
   end
 
   def allow_delete current_user
-    (self.is_invalid && (current_user == self.user || current_user.admin?)) ||
-        (self.score.nil? && current_user == self.user)
+    (self.is_invalid || self.score.nil?) && (current_user == self.user || current_user.admin?)
   end
 
   # 匿评分