diff --git a/src/concurrency/index.md b/src/concurrency/index.md
index 5c606c62..54c00fa0 100644
--- a/src/concurrency/index.md
+++ b/src/concurrency/index.md
@@ -552,23 +552,6 @@ fn timer() {
 
 ```
 
-> **NOTE**
->
-> At the moment, the `cortex-m` crate hides const versions of some functions
-> (including `Mutex::new()`) behind the `const-fn` feature. So you need to add
-> the `const-fn` feature as a dependency for cortex-m in the Cargo.toml to make
-> the above examples work:
->
-> ``` toml
-> [dependencies.cortex-m]
-> version="0.6.0"
-> features=["const-fn"]
-> ```
-> Meanwhile, `const-fn` has been working on stable Rust for some time now.
-> So this additional switch in Cargo.toml will not be needed as soon as 
-> it is enabled in `cortex-m` by default.
->
-
 Whew! This is safe, but it is also a little unwieldy. Is there anything else
 we can do?