diff --git a/core/src/session.rs b/core/src/session.rs
index cb210a0f..af1c12cc 100644
--- a/core/src/session.rs
+++ b/core/src/session.rs
@@ -1,6 +1,4 @@
 use bytes::Bytes;
-use crypto::digest::Digest;
-use crypto::sha1::Sha1;
 use futures::{Async, Future, IntoFuture, Poll, Stream};
 use futures::sync::mpsc;
 use std::io;
@@ -45,12 +43,6 @@ static SESSION_COUNTER: AtomicUsize = ATOMIC_USIZE_INIT;
 #[derive(Clone)]
 pub struct Session(Arc<SessionInternal>);
 
-pub fn device_id(name: &str) -> String {
-    let mut h = Sha1::new();
-    h.input_str(name);
-    h.result_str()
-}
-
 impl Session {
     pub fn connect(
         config: SessionConfig,
diff --git a/core/src/util/int128.rs b/core/src/util/int128.rs
index f79692ca..648c5aae 100644
--- a/core/src/util/int128.rs
+++ b/core/src/util/int128.rs
@@ -2,7 +2,7 @@ use std;
 
 #[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
 #[allow(non_camel_case_types)]
-pub struct u128 {
+pub(crate) struct u128 {
     high: u64,
     low: u64,
 }
diff --git a/core/src/util/mod.rs b/core/src/util/mod.rs
index 9c373eaa..a41638bc 100644
--- a/core/src/util/mod.rs
+++ b/core/src/util/mod.rs
@@ -7,7 +7,7 @@ use std::ops::{Mul, Rem, Shr};
 
 mod int128;
 
-pub use util::int128::u128;
+pub(crate) use util::int128::u128;
 
 pub fn rand_vec<G: Rng, R: Rand>(rng: &mut G, size: usize) -> Vec<R> {
     rng.gen_iter().take(size).collect()
diff --git a/src/main.rs b/src/main.rs
index 01c34421..0a9c2ad3 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -6,6 +6,7 @@ extern crate librespot;
 extern crate tokio_core;
 extern crate tokio_io;
 extern crate tokio_signal;
+extern crate crypto;
 
 use env_logger::LogBuilder;
 use futures::{Future, Async, Poll, Stream};
@@ -17,6 +18,8 @@ use std::str::FromStr;
 use tokio_core::reactor::{Handle, Core};
 use tokio_io::IoStream;
 use std::mem;
+use crypto::digest::Digest;
+use crypto::sha1::Sha1;
 
 use librespot::core::authentication::{get_credentials, Credentials};
 use librespot::core::cache::Cache;
@@ -31,6 +34,12 @@ use librespot::playback::mixer::{self, Mixer};
 use librespot::playback::player::Player;
 use librespot::connect::spirc::{Spirc, SpircTask};
 
+fn device_id(name: &str) -> String {
+    let mut h = Sha1::new();
+    h.input_str(name);
+    h.result_str()
+}
+
 fn usage(program: &str, opts: &getopts::Options) -> String {
     let brief = format!("Usage: {} [options]", program);
     opts.usage(&brief)
@@ -170,7 +179,7 @@ fn setup(args: &[String]) -> Setup {
     };
 
     let session_config = {
-        let device_id = librespot::core::session::device_id(&name);
+        let device_id = device_id(&name);
 
         SessionConfig {
             user_agent: version::version_string(),