README.md in mutex_m-0.1.2 vs README.md in mutex_m-0.2.0

@@ -21,10 +21,10 @@
 ## Usage
 
 Start by requiring the standard library Mutex_m:
 
 ```ruby
-require "mutex_m.rb"
+require "mutex_m"
 ```
 
 From here you can extend an object with Mutex instance methods:
 
 ```ruby