diff --git a/components/servo/Cargo.lock b/components/servo/Cargo.lock
index 4d7eafe1116..503a8a4c628 100644
--- a/components/servo/Cargo.lock
+++ b/components/servo/Cargo.lock
@@ -1425,11 +1425,8 @@ name = "num"
 version = "0.1.32"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "num-bigint 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
- "num-complex 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
  "num-integer 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
  "num-iter 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
- "num-rational 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
  "num-traits 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -1444,15 +1441,6 @@ dependencies = [
  "rustc-serialize 0.3.19 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
-[[package]]
-name = "num-complex"
-version = "0.1.32"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "num-traits 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
- "rustc-serialize 0.3.19 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
 [[package]]
 name = "num-integer"
 version = "0.1.32"
@@ -2350,7 +2338,7 @@ dependencies = [
  "lazy_static 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
- "num 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
+ "num-traits 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
  "num_cpus 0.2.12 (registry+https://github.com/rust-lang/crates.io-index)",
  "plugins 0.0.1",
  "rand 0.3.14 (registry+https://github.com/rust-lang/crates.io-index)",
diff --git a/components/util/Cargo.toml b/components/util/Cargo.toml
index 4373de0a040..a6d5877a7ad 100644
--- a/components/util/Cargo.toml
+++ b/components/util/Cargo.toml
@@ -31,8 +31,8 @@ js = {git = "https://github.com/servo/rust-mozjs", optional = true}
 lazy_static = "0.2"
 libc = "0.2"
 log = "0.3.5"
-num = "0.1.32"
 num_cpus = "0.2.2"
+num-traits = "0.1.32"
 plugins = {path = "../plugins"}
 rand = "0.3"
 rustc-serialize = "0.3"
diff --git a/components/util/lib.rs b/components/util/lib.rs
index c98d3eebf3b..b9c349fee6a 100644
--- a/components/util/lib.rs
+++ b/components/util/lib.rs
@@ -34,8 +34,8 @@ extern crate lazy_static;
 extern crate libc;
 #[macro_use]
 extern crate log;
-extern crate num;
 extern crate num_cpus;
+extern crate num_traits;
 extern crate rand;
 extern crate rustc_serialize;
 extern crate serde;
diff --git a/components/util/str.rs b/components/util/str.rs
index 997aee8f53c..1dcce6ee14a 100644
--- a/components/util/str.rs
+++ b/components/util/str.rs
@@ -4,7 +4,7 @@
 
 use app_units::Au;
 use libc::c_char;
-use num::ToPrimitive;
+use num_traits::ToPrimitive;
 use std::borrow::ToOwned;
 use std::convert::AsRef;
 use std::ffi::CStr;
diff --git a/ports/cef/Cargo.lock b/ports/cef/Cargo.lock
index 32dd643dc3b..f4ce61f2d42 100644
--- a/ports/cef/Cargo.lock
+++ b/ports/cef/Cargo.lock
@@ -1305,11 +1305,8 @@ name = "num"
 version = "0.1.32"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "num-bigint 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
- "num-complex 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
  "num-integer 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
  "num-iter 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
- "num-rational 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
  "num-traits 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -1324,15 +1321,6 @@ dependencies = [
  "rustc-serialize 0.3.19 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
-[[package]]
-name = "num-complex"
-version = "0.1.32"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "num-traits 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
- "rustc-serialize 0.3.19 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
 [[package]]
 name = "num-integer"
 version = "0.1.32"
@@ -2219,7 +2207,7 @@ dependencies = [
  "lazy_static 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
- "num 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
+ "num-traits 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
  "num_cpus 0.2.12 (registry+https://github.com/rust-lang/crates.io-index)",
  "plugins 0.0.1",
  "rand 0.3.14 (registry+https://github.com/rust-lang/crates.io-index)",
diff --git a/ports/geckolib/Cargo.lock b/ports/geckolib/Cargo.lock
index d4b1e99d5f6..090f12e7724 100644
--- a/ports/geckolib/Cargo.lock
+++ b/ports/geckolib/Cargo.lock
@@ -311,67 +311,6 @@ dependencies = [
  "libc 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
-[[package]]
-name = "num"
-version = "0.1.32"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "num-bigint 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
- "num-complex 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
- "num-integer 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
- "num-iter 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
- "num-rational 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
- "num-traits 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
-[[package]]
-name = "num-bigint"
-version = "0.1.32"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "num-integer 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
- "num-traits 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
- "rand 0.3.14 (registry+https://github.com/rust-lang/crates.io-index)",
- "rustc-serialize 0.3.19 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
-[[package]]
-name = "num-complex"
-version = "0.1.32"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "num-traits 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
- "rustc-serialize 0.3.19 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
-[[package]]
-name = "num-integer"
-version = "0.1.32"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "num-traits 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
-[[package]]
-name = "num-iter"
-version = "0.1.32"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "num-integer 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
- "num-traits 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
-[[package]]
-name = "num-rational"
-version = "0.1.32"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "num-bigint 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
- "num-integer 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
- "num-traits 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
- "rustc-serialize 0.3.19 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
 [[package]]
 name = "num-traits"
 version = "0.1.32"
@@ -656,7 +595,7 @@ dependencies = [
  "lazy_static 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
- "num 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
+ "num-traits 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
  "num_cpus 0.2.12 (registry+https://github.com/rust-lang/crates.io-index)",
  "plugins 0.0.1",
  "rand 0.3.14 (registry+https://github.com/rust-lang/crates.io-index)",
diff --git a/ports/gonk/Cargo.lock b/ports/gonk/Cargo.lock
index 052bf9983d1..c589816ed5b 100644
--- a/ports/gonk/Cargo.lock
+++ b/ports/gonk/Cargo.lock
@@ -1297,11 +1297,8 @@ name = "num"
 version = "0.1.32"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "num-bigint 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
- "num-complex 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
  "num-integer 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
  "num-iter 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
- "num-rational 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
  "num-traits 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -1316,15 +1313,6 @@ dependencies = [
  "rustc-serialize 0.3.19 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
-[[package]]
-name = "num-complex"
-version = "0.1.32"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "num-traits 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
- "rustc-serialize 0.3.19 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
 [[package]]
 name = "num-integer"
 version = "0.1.32"
@@ -2209,7 +2197,7 @@ dependencies = [
  "lazy_static 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
- "num 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
+ "num-traits 0.1.32 (registry+https://github.com/rust-lang/crates.io-index)",
  "num_cpus 0.2.12 (registry+https://github.com/rust-lang/crates.io-index)",
  "plugins 0.0.1",
  "rand 0.3.14 (registry+https://github.com/rust-lang/crates.io-index)",