diff --git a/.travis.yml b/.travis.yml
index b177ce6..84592de 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,4 +1,6 @@
 language: rust
+rust:
+  - nightly
 sudo: false
 
 script:
diff --git a/src/length.rs b/src/length.rs
index 7ffc59d..2cc7d9e 100644
--- a/src/length.rs
+++ b/src/length.rs
@@ -136,11 +136,11 @@ mod tests {
 
     #[test]
     fn test_length() {
-        let mm_per_inch: ScaleFactor<Inch, Mm, f32> = ScaleFactor(25.4);
+        let mm_per_inch: ScaleFactor<Inch, Mm, f32> = ScaleFactor::new(25.4);
 
         let one_foot: Length<Inch, f32> = Length::new(12.0);
-        let two_feet = one_foot + one_foot;
-        let zero_feet = one_foot - one_foot;
+        let two_feet = one_foot.clone() + one_foot.clone();
+        let zero_feet = one_foot.clone() - one_foot.clone();
 
         assert_eq!(one_foot.get(), 12.0);
         assert_eq!(two_feet.get(), 24.0);
@@ -159,14 +159,14 @@ mod tests {
         assert!(!(two_feet >  two_feet));
         assert!(!(two_feet <  two_feet));
 
-        let one_foot_in_mm: Length<Mm, f32> = one_foot * mm_per_inch;
+        let one_foot_in_mm: Length<Mm, f32> = one_foot.clone() * mm_per_inch.clone();
 
         assert_eq!(one_foot_in_mm, Length::new(304.8));
 
         let back_to_inches: Length<Inch, f32> = one_foot_in_mm / mm_per_inch;
         assert_eq!(one_foot, back_to_inches);
 
-        let int_foot: Length<Inch, int> = one_foot.cast().unwrap();
+        let int_foot: Length<Inch, isize> = one_foot.cast().unwrap();
         assert_eq!(int_foot.get(), 12);
 
         let negative_one_foot = -one_foot;
diff --git a/src/scale_factor.rs b/src/scale_factor.rs
index 54791ef..7cf389e 100644
--- a/src/scale_factor.rs
+++ b/src/scale_factor.rs
@@ -28,9 +28,9 @@ use std::marker::PhantomData;
 /// enum Mm {};
 /// enum Inch {};
 ///
-/// let mm_per_inch: ScaleFactor<Inch, Mm, f32> = ScaleFactor(25.4);
+/// let mm_per_inch: ScaleFactor<Inch, Mm, f32> = ScaleFactor::new(25.4);
 ///
-/// let one_foot: Length<Inch, f32> = Length(12.0);
+/// let one_foot: Length<Inch, f32> = Length::new(12.0);
 /// let one_foot_in_mm: Length<Mm, f32> = one_foot * mm_per_inch;
 /// ```
 #[derive(Copy, RustcDecodable, RustcEncodable, Debug)]
@@ -128,11 +128,11 @@ mod tests {
         let cm_per_inch: ScaleFactor<Inch, Cm, f32> = mm_per_inch * cm_per_mm;
         assert_eq!(cm_per_inch, ScaleFactor::new(2.54));
 
-        let a: ScaleFactor<Inch, Inch, int> = ScaleFactor::new(2);
-        let b: ScaleFactor<Inch, Inch, int> = ScaleFactor::new(3);
+        let a: ScaleFactor<Inch, Inch, isize> = ScaleFactor::new(2);
+        let b: ScaleFactor<Inch, Inch, isize> = ScaleFactor::new(3);
         assert!(a != b);
         assert_eq!(a, a.clone());
-        assert_eq!(a + b, ScaleFactor::new(5));
+        assert_eq!(a.clone() + b.clone(), ScaleFactor::new(5));
         assert_eq!(a - b, ScaleFactor::new(-1));
     }
 }