diff --git a/contrib/advanced-python/index.md b/contrib/advanced-python/index.md
index fa2fd7b..16210c2 100644
--- a/contrib/advanced-python/index.md
+++ b/contrib/advanced-python/index.md
@@ -1,6 +1,6 @@
 # List of sections
 
-- [OOPs](OOPs.md)
+- [OOPs](oops.md)
 - [Decorators/\*args/**kwargs](decorator-kwargs-args.md)
 - [Lambda Function](lambda-function.md)
 - [Working with Dates & Times in Python](dates_and_times.md)