diff --git a/docs/数据库系统/15445.en.md b/docs/数据库系统/15445.en.md
index 5ce7ba68..a40fcf16 100644
--- a/docs/数据库系统/15445.en.md
+++ b/docs/数据库系统/15445.en.md
@@ -12,7 +12,7 @@ As an introductory course of database at CMU, this course is taught by Andy Pavl
 
 ## Resources
 
-- Course Website: [Fall2019](https://15445.courses.cs.cmu.edu/fall2019/schedule.html), [Fall2020](https://15445.courses.cs.cmu.edu/fall2020/schedule.html), [Fall2021]((https://15445.courses.cs.cmu.edu/fall2021/schedule.html)
+- Course Website: [Fall2019](https://15445.courses.cs.cmu.edu/fall2019/schedule.html), [Fall2020](https://15445.courses.cs.cmu.edu/fall2020/schedule.html), [Fall2021](https://15445.courses.cs.cmu.edu/fall2021/schedule.html)
 - Assignments: refer to the course website
 - Textbook: Database System Concepts
 - Assignments: 4 Projects