diff --git a/src/libcore/iter/mod.rs b/src/libcore/iter/mod.rs
index 8ae4b53da95b..62e1f9fcb640 100644
--- a/src/libcore/iter/mod.rs
+++ b/src/libcore/iter/mod.rs
@@ -112,10 +112,10 @@
 //!
 //!     // next() is the only required method
 //!     fn next(&mut self) -> Option<usize> {
-//!         // increment our count. This is why we started at zero.
+//!         // Increment our count. This is why we started at zero.
 //!         self.count += 1;
 //!
-//!         // check to see if we've finished counting or not.
+//!         // Check to see if we've finished counting or not.
 //!         if self.count < 6 {
 //!             Some(self.count)
 //!         } else {
diff --git a/src/libcore/iter/sources.rs b/src/libcore/iter/sources.rs
index 6d35d5464153..f6a4a7a6fa80 100644
--- a/src/libcore/iter/sources.rs
+++ b/src/libcore/iter/sources.rs
@@ -415,10 +415,10 @@ pub fn once<T>(value: T) -> Once<T> {
 /// ```
 /// #![feature(iter_unfold)]
 /// let counter = std::iter::unfold(0, |count| {
-///     // increment our count. This is why we started at zero.
+///     // Increment our count. This is why we started at zero.
 ///     *count += 1;
 ///
-///     // check to see if we've finished counting or not.
+///     // Check to see if we've finished counting or not.
 ///     if *count < 6 {
 ///         Some(*count)
 ///     } else {