diff --git a/Cargo.toml b/Cargo.toml
index a61366b..5d40523 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,7 +1,7 @@
 [package]
 
 name = "num"
-version = "0.1.3"
+version = "0.1.4"
 authors = ["The Rust Project Developers"]
 license = "MIT/Apache-2.0"
 homepage = "https://github.com/rust-lang/num"
@@ -14,4 +14,4 @@ rational, and complex types.
 """
 
 [dependencies]
-rustc-serialize = "0.1"
+rustc-serialize = "0.2"
diff --git a/src/lib.rs b/src/lib.rs
index 51e74be..58ef857 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -22,6 +22,7 @@
 //! ```
 //! extern crate num;
 //!
+//! use std::num::FromPrimitive;
 //! use num::bigint::BigInt;
 //! use num::rational::{Ratio, BigRational};
 //!