diff --git a/src/doc/book/concurrency.md b/src/doc/book/concurrency.md
index 991654b2b8d..87d551b68df 100644
--- a/src/doc/book/concurrency.md
+++ b/src/doc/book/concurrency.md
@@ -271,7 +271,7 @@ fn main() {
 }
 ```
 
-Similarly to las time, we use `clone()` to create a new owned handle.
+Similarly to last time, we use `clone()` to create a new owned handle.
 This handle is then moved into the new thread.
 
 And... still gives us an error.
@@ -282,7 +282,7 @@ And... still gives us an error.
                              ^~~~
 ```
 
-`Arc<T> by default has immutable contents. It allows the _sharing_ of data
+`Arc<T>` by default has immutable contents. It allows the _sharing_ of data
 between threads, but shared mutable data is unsafe and when threads are
 involved can cause data races!