diff --git a/book/en/src/internals/targets.md b/book/en/src/internals/targets.md
index 4972e5fcb3..da55937157 100644
--- a/book/en/src/internals/targets.md
+++ b/book/en/src/internals/targets.md
@@ -53,7 +53,7 @@ showing two tasks A and B where A has higher priority but shares a resource with
 At time *t1*, task B locks the shared resource by selectively disabling all other tasks which share 
 the resource using the NVIC. In effect this raises the virtual priority ceiling. Task A is one such
 task that shares resources with task B. At time *t2*, task A is either spawned by task B or becomes 
-pending through an interrupt condition, but does not yet preempt task B even though it's priority is 
+pending through an interrupt condition, but does not yet preempt task B even though its priority is 
 greater. This is because the NVIC is preventing it from starting due to task A's source mask being 
 disabled. At time *t3*, task B releases the lock by re-enabling the tasks in the NVIC. Because 
 task A was pending and has a higher priority than task B, it immediately preempts task B and is