diff --git a/app/models/comment.rb b/app/models/comment.rb
index 9de25c50d..473283dc0 100644
--- a/app/models/comment.rb
+++ b/app/models/comment.rb
@@ -81,8 +81,10 @@ class Comment < ActiveRecord::Base
 
   # 课程成员得分（英雄榜）
   def act_as_student_score
-    unless self.author.allowed_to?(:as_teacher, self.commented.course)
-      course_member_score(self.commented.course.id, self.author_id, "NewReply")
+    if self.commented.course
+      unless self.author.allowed_to?(:as_teacher, self.commented.course)
+        course_member_score(self.commented.course.id, self.author_id, "NewReply")
+      end
     end
   end
 
diff --git a/app/models/message.rb b/app/models/message.rb
index 21e5e1c71..3f9057346 100644
--- a/app/models/message.rb
+++ b/app/models/message.rb
@@ -287,13 +287,15 @@ class Message < ActiveRecord::Base
 
   # 课程成员得分（英雄榜）
   def act_as_student_score
-    unless  self.author.allowed_to?(:as_teacher, self.course)
-      if self.parent_id.nil?
-        # 发帖
-        course_member_score(self.course.id, self.author_id, "Message")
-      else
-        # 回帖
-        course_member_score(self.course.id, self.author_id, "MessageReply")
+    if self.course
+      unless  self.author.allowed_to?(:as_teacher, self.course)
+        if self.parent_id.nil?
+          # 发帖
+          course_member_score(self.course.id, self.author_id, "Message")
+        else
+          # 回帖
+          course_member_score(self.course.id, self.author_id, "MessageReply")
+        end
       end
     end
   end