diff --git a/src/libcore/core.rc b/src/libcore/core.rc
index 7890d611e853..2a8de6a80322 100644
--- a/src/libcore/core.rc
+++ b/src/libcore/core.rc
@@ -103,7 +103,8 @@ pub use iter::{BaseIter, ExtendedIter, EqIter, CopyableIter};
 pub use iter::{CopyableOrderedIter, CopyableNonstrictIter, Times};
 pub use iter::{ExtendedMutableIter};
 
-pub use num::{Num, Signed, Unsigned, Natural, NumCast};
+pub use num::{Num, NumCast};
+pub use num::{Signed, Unsigned, Integer};
 pub use ptr::Ptr;
 pub use to_str::ToStr;
 pub use clone::Clone;
diff --git a/src/libcore/num/int-template.rs b/src/libcore/num/int-template.rs
index cb29b9e44863..e322e5edeb90 100644
--- a/src/libcore/num/int-template.rs
+++ b/src/libcore/num/int-template.rs
@@ -279,7 +279,7 @@ impl Signed for T {
     fn is_negative(&self) -> bool { *self < 0 }
 }
 
-impl Natural for T {
+impl Integer for T {
     /**
      * Floored integer division
      *
diff --git a/src/libcore/num/num.rs b/src/libcore/num/num.rs
index 8304179c346a..1c3c699603b0 100644
--- a/src/libcore/num/num.rs
+++ b/src/libcore/num/num.rs
@@ -61,7 +61,7 @@ pub fn abs<T:Ord + Zero + Neg<T>>(v: T) -> T {
     if v < Zero::zero() { v.neg() } else { v }
 }
 
-pub trait Natural: Num
+pub trait Integer: Num
                  + Ord
                  + Quot<Self,Self>
                  + Rem<Self,Self> {
diff --git a/src/libcore/num/uint-template.rs b/src/libcore/num/uint-template.rs
index 2ee64d4e4eaa..69483f33e528 100644
--- a/src/libcore/num/uint-template.rs
+++ b/src/libcore/num/uint-template.rs
@@ -176,7 +176,7 @@ impl Neg<T> for T {
 
 impl Unsigned for T {}
 
-impl Natural for T {
+impl Integer for T {
     /// Unsigned integer division. Returns the same result as `quot` (`/`).
     #[inline(always)]
     fn div(&self, other: T) -> T { *self / other }
diff --git a/src/libcore/prelude.rs b/src/libcore/prelude.rs
index 0af0cdf08c91..ec332adb8323 100644
--- a/src/libcore/prelude.rs
+++ b/src/libcore/prelude.rs
@@ -37,7 +37,8 @@ pub use hash::Hash;
 pub use iter::{BaseIter, ReverseIter, MutableIter, ExtendedIter, EqIter};
 pub use iter::{CopyableIter, CopyableOrderedIter, CopyableNonstrictIter};
 pub use iter::{Times, ExtendedMutableIter};
-pub use num::{Num, Signed, Unsigned, Natural, NumCast};
+pub use num::{Num, NumCast};
+pub use num::{Signed, Unsigned, Integer};
 pub use path::GenericPath;
 pub use path::Path;
 pub use path::PosixPath;