diff --git a/Cargo.toml b/Cargo.toml
index e5af2f7..c46bffc 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -17,7 +17,6 @@ travis-ci = { repository = "isislovecruft/ed25519-dalek", branch = "master"}
 
 [dependencies]
 arrayref = "0.3.3"
-sha2 = "^0.4"
 
 [dependencies.curve25519-dalek]
 version = "^0.6"
@@ -37,6 +36,7 @@ version = "^0.6"
 [dev-dependencies]
 rustc-serialize = "0.3"
 blake2 = "^0.4"
+sha2 = "^0.4"
 
 [features]
 default = ["std"]
diff --git a/src/ed25519.rs b/src/ed25519.rs
index 87d38d7..7c483ba 100644
--- a/src/ed25519.rs
+++ b/src/ed25519.rs
@@ -12,8 +12,6 @@
 
 use core::fmt::Debug;
 
-use sha2::Sha512;
-
 #[cfg(feature = "std")]
 use rand::Rng;
 
@@ -392,6 +390,7 @@ mod test {
     use curve25519_dalek::curve::ExtendedPoint;
     use rand::OsRng;
     use rustc_serialize::hex::FromHex;
+    use sha2::Sha512;
     use super::*;
 
     #[test]
@@ -499,6 +498,7 @@ mod bench {
     use digest::Digest;
     use test::Bencher;
     use rand::OsRng;
+    use sha2::Sha512;
     use super::*;
 
     /// A fake RNG which simply returns zeroes.