diff --git a/SyncPrim/README.md b/SyncPrim/README.md
index b57fe8b..f8ab43a 100644
--- a/SyncPrim/README.md
+++ b/SyncPrim/README.md
@@ -5,3 +5,4 @@ This chapter describes synchronization primitivies in the Linux kernel.
 * [Introduction to spinlocks](http://0xax.gitbooks.io/linux-insides/content/SyncPrim/sync-1.html) - the first part of this chapter describes implementation of spinlock mechanism in the Linux kernel.
 * [Queued spinlocks](https://0xax.gitbooks.io/linux-insides/content/SyncPrim/sync-2.html) - the second part describes another type of spinlocks - queued spinlocks.
 * [Semaphores](https://0xax.gitbooks.io/linux-insides/content/SyncPrim/sync-3.html) - this part describes implementation of `semaphore` synchronization primitive in the Linux kernel.
+* [Mutual exclusion](https://0xax.gitbooks.io/linux-insides/content/SyncPrim/sync-4.html) - this part describes - `mutex` in the Linux kernel.