diff --git a/Cargo.toml b/Cargo.toml
index 593e4bf..d17516e 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -8,3 +8,4 @@ git = "https://github.com/tedsta/gpuarray-rs"
 
 [dependencies]
 rand = "*"
+num = "*"
diff --git a/src/util.rs b/src/util.rs
index 342002d..2db1341 100644
--- a/src/util.rs
+++ b/src/util.rs
@@ -1,4 +1,5 @@
-use std::num::{Zero, One};
+extern crate num;
+use self::num::{Zero, One};
 
 use ga::Array;