diff --git a/README.md b/README.md
index f1a17859e0d..75950ed4838 100644
--- a/README.md
+++ b/README.md
@@ -51,7 +51,7 @@ fn main() {
   // type, range, distribution, etc.
   let mut rng = thread_rng();
   if rng.gen() { // random bool
-      let x: f64 = rng.gen(); // random number in range (0, 1)
+      let x: f64 = rng.gen(); // random number in range [0, 1)
       println!("x is: {}", x);
       let ch = rng.gen::<char>(); // Sometimes you need type annotation
       println!("char is: {}", ch);
diff --git a/src/lib.rs b/src/lib.rs
index 3723754cf7b..eb23f86b87f 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -111,7 +111,7 @@
 //! let mut rng = thread_rng();
 //! 
 //! if rng.gen() { // random bool
-//!     let x: f64 = rng.gen(); // random number in range (0, 1)
+//!     let x: f64 = rng.gen(); // random number in range [0, 1)
 //!     println!("x is: {}", x);
 //!     let ch = rng.gen::<char>(); // using type annotation
 //!     println!("char is: {}", ch);