diff --git a/test/unit/course_test.rb b/test/unit/course_test.rb
index a29501066..86963eb4b 100644
--- a/test/unit/course_test.rb
+++ b/test/unit/course_test.rb
@@ -7,8 +7,8 @@ class CourseTest < ActiveSupport::TestCase
   end
 
   test 'name valid with CJK coding' do
-    course = Course.find_by_id(74)
     name_quirk = '电路与电子学基础（软件工程专业）'
+    course = Course.find_by_id(74)
     course.name = "test_course"
     assert course.valid?
     course.name = name_quirk
@@ -17,9 +17,9 @@ class CourseTest < ActiveSupport::TestCase
 
   test 'description too long must be valid.' do
     course = Course.find_by_id(8)
-    course.description = course.description * 100
+    course.description = 'a' * 2048 # description length validate.
     course.valid?
-    assert_equal course.errors.full_messages.count, 0
+    assert course.errors[:name].empty?
     assert course.valid?
   end