diff --git a/core/src/cache.rs b/core/src/cache.rs
index 28b787ff..1a58bdc0 100644
--- a/core/src/cache.rs
+++ b/core/src/cache.rs
@@ -1,8 +1,11 @@
-use std::path::PathBuf;
-use std::io::Read;
+use std::fs;
 use std::fs::File;
+use std::io;
+use std::io::Read;
+use std::path::Path;
+use std::path::PathBuf;
 
-use util::{FileId, mkdir_existing};
+use util::FileId;
 use authentication::Credentials;
 
 #[derive(Clone)]
@@ -11,6 +14,16 @@ pub struct Cache {
     use_audio_cache: bool,
 }
 
+fn mkdir_existing(path: &Path) -> io::Result<()> {
+    fs::create_dir(path).or_else(|err| {
+        if err.kind() == io::ErrorKind::AlreadyExists {
+            Ok(())
+        } else {
+            Err(err)
+        }
+    })
+}
+
 impl Cache {
     pub fn new(location: PathBuf, use_audio_cache: bool) -> Cache {
         mkdir_existing(&location).unwrap();
diff --git a/core/src/mercury/sender.rs b/core/src/mercury/sender.rs
index 67b4dc08..359e6907 100644
--- a/core/src/mercury/sender.rs
+++ b/core/src/mercury/sender.rs
@@ -11,7 +11,7 @@ pub struct MercurySender {
 
 impl MercurySender {
     // TODO: pub(super) when stable
-    pub fn new(mercury: MercuryManager, uri: String) -> MercurySender {
+    pub(crate) fn new(mercury: MercuryManager, uri: String) -> MercurySender {
         MercurySender {
             mercury: mercury,
             uri: uri,
diff --git a/core/src/session.rs b/core/src/session.rs
index e3b474bf..9fe785ed 100644
--- a/core/src/session.rs
+++ b/core/src/session.rs
@@ -184,7 +184,7 @@ impl Session {
         self.0.cache.as_ref()
     }
 
-    pub fn config(&self) -> &SessionConfig {
+    fn config(&self) -> &SessionConfig {
         &self.0.config
     }
 
@@ -200,7 +200,7 @@ impl Session {
         &self.config().device_id
     }
 
-    pub fn weak(&self) -> SessionWeak {
+    fn weak(&self) -> SessionWeak {
         SessionWeak(Arc::downgrade(&self.0))
     }
 
@@ -213,11 +213,11 @@ impl Session {
 pub struct SessionWeak(pub Weak<SessionInternal>);
 
 impl SessionWeak {
-    pub fn try_upgrade(&self) -> Option<Session> {
+    fn try_upgrade(&self) -> Option<Session> {
         self.0.upgrade().map(Session)
     }
 
-    pub fn upgrade(&self) -> Session {
+    pub(crate) fn upgrade(&self) -> Session {
         self.try_upgrade().expect("Session died")
     }
 }
diff --git a/core/src/util/mod.rs b/core/src/util/mod.rs
index 01a3a506..6e21a0f2 100644
--- a/core/src/util/mod.rs
+++ b/core/src/util/mod.rs
@@ -2,54 +2,19 @@ use num_bigint::BigUint;
 use num_traits::{Zero, One};
 use num_integer::Integer;
 use rand::{Rng, Rand};
-use std::io;
 use std::mem;
 use std::ops::{Mul, Rem, Shr};
-use std::fs;
-use std::path::Path;
-use std::process::Command;
-use std::time::{UNIX_EPOCH, SystemTime};
 
 mod int128;
 mod spotify_id;
-mod subfile;
 
 pub use util::int128::u128;
 pub use util::spotify_id::{SpotifyId, FileId};
-pub use util::subfile::Subfile;
 
 pub fn rand_vec<G: Rng, R: Rand>(rng: &mut G, size: usize) -> Vec<R> {
     rng.gen_iter().take(size).collect()
 }
 
-pub fn now_ms() -> i64 {
-    let dur = match SystemTime::now().duration_since(UNIX_EPOCH) {
-        Ok(dur) => dur,
-        Err(err) => err.duration(),
-    };
-    (dur.as_secs() * 1000 + (dur.subsec_nanos() / 1000_000) as u64) as i64
-}
-
-pub fn mkdir_existing(path: &Path) -> io::Result<()> {
-    fs::create_dir(path).or_else(|err| {
-        if err.kind() == io::ErrorKind::AlreadyExists {
-            Ok(())
-        } else {
-            Err(err)
-        }
-    })
-}
-
-pub fn run_program(program: &str) {
-    info!("Running {}", program);
-    let mut v: Vec<&str> = program.split_whitespace().collect();
-    let status = Command::new(&v.remove(0))
-            .args(&v)
-            .status()
-            .expect("program failed to start");
-    info!("Exit status: {}", status);
-}
-
 pub fn powm(base: &BigUint, exp: &BigUint, modulus: &BigUint) -> BigUint {
     let mut base = base.clone();
     let mut exp = exp.clone();
diff --git a/core/src/util/subfile.rs b/core/src/util/subfile.rs
deleted file mode 100644
index 81d5d916..00000000
--- a/core/src/util/subfile.rs
+++ /dev/null
@@ -1,38 +0,0 @@
-use std::io::{Read, Seek, SeekFrom, Result};
-
-pub struct Subfile<T: Read + Seek> {
-    stream: T,
-    offset: u64,
-}
-
-impl<T: Read + Seek> Subfile<T> {
-    pub fn new(mut stream: T, offset: u64) -> Subfile<T> {
-        stream.seek(SeekFrom::Start(offset)).unwrap();
-        Subfile {
-            stream: stream,
-            offset: offset,
-        }
-    }
-}
-
-impl<T: Read + Seek> Read for Subfile<T> {
-    fn read(&mut self, buf: &mut [u8]) -> Result<usize> {
-        self.stream.read(buf)
-    }
-}
-
-impl<T: Read + Seek> Seek for Subfile<T> {
-    fn seek(&mut self, mut pos: SeekFrom) -> Result<u64> {
-        pos = match pos {
-            SeekFrom::Start(offset) => SeekFrom::Start(offset + self.offset),
-            x => x,
-        };
-
-        let newpos = try!(self.stream.seek(pos));
-        if newpos > self.offset {
-            Ok(newpos - self.offset)
-        } else {
-            Ok(0)
-        }
-    }
-}
diff --git a/playback/src/player.rs b/playback/src/player.rs
index ffffa130..f0ee5d22 100644
--- a/playback/src/player.rs
+++ b/playback/src/player.rs
@@ -1,15 +1,17 @@
 use futures::sync::oneshot;
 use futures::{future, Future};
+use std;
 use std::borrow::Cow;
+use std::io::{Read, Seek, SeekFrom, Result};
 use std::mem;
+use std::process::Command;
 use std::sync::mpsc::{RecvError, TryRecvError, RecvTimeoutError};
 use std::thread;
 use std::time::Duration;
-use std;
 
 use core::config::{Bitrate, PlayerConfig};
 use core::session::Session;
-use core::util::{self, SpotifyId, Subfile};
+use core::util::SpotifyId;
 
 use audio_backend::Sink;
 use audio::{AudioFile, AudioDecrypt};
@@ -375,13 +377,13 @@ impl PlayerInternal {
 
     fn run_onstart(&self) {
         if let Some(ref program) = self.config.onstart {
-            util::run_program(program)
+            run_program(program)
         }
     }
 
     fn run_onstop(&self) {
         if let Some(ref program) = self.config.onstop {
-            util::run_program(program)
+            run_program(program)
         }
     }
 
@@ -478,3 +480,50 @@ impl ::std::fmt::Debug for PlayerCommand {
         }
     }
 }
+
+struct Subfile<T: Read + Seek> {
+    stream: T,
+    offset: u64,
+}
+
+impl<T: Read + Seek> Subfile<T> {
+    pub fn new(mut stream: T, offset: u64) -> Subfile<T> {
+        stream.seek(SeekFrom::Start(offset)).unwrap();
+        Subfile {
+            stream: stream,
+            offset: offset,
+        }
+    }
+}
+
+impl<T: Read + Seek> Read for Subfile<T> {
+    fn read(&mut self, buf: &mut [u8]) -> Result<usize> {
+        self.stream.read(buf)
+    }
+}
+
+impl<T: Read + Seek> Seek for Subfile<T> {
+    fn seek(&mut self, mut pos: SeekFrom) -> Result<u64> {
+        pos = match pos {
+            SeekFrom::Start(offset) => SeekFrom::Start(offset + self.offset),
+            x => x,
+        };
+
+        let newpos = try!(self.stream.seek(pos));
+        if newpos > self.offset {
+            Ok(newpos - self.offset)
+        } else {
+            Ok(0)
+        }
+    }
+}
+
+fn run_program(program: &str) {
+    info!("Running {}", program);
+    let mut v: Vec<&str> = program.split_whitespace().collect();
+    let status = Command::new(&v.remove(0))
+            .args(&v)
+            .status()
+            .expect("program failed to start");
+    info!("Exit status: {}", status);
+}
diff --git a/src/spirc.rs b/src/spirc.rs
index 5c3d2afe..a34be279 100644
--- a/src/spirc.rs
+++ b/src/spirc.rs
@@ -6,7 +6,7 @@ use protobuf::{self, Message};
 use core::config::ConnectConfig;
 use core::mercury::MercuryError;
 use core::session::Session;
-use core::util::{now_ms, SpotifyId, SeqGenerator};
+use core::util::{SpotifyId, SeqGenerator};
 use core::version;
 
 use protocol;
@@ -18,6 +18,7 @@ use playback::player::Player;
 use std;
 use rand;
 use rand::Rng;
+use std::time::{UNIX_EPOCH, SystemTime};
 
 pub struct SpircTask {
     player: Player,
@@ -53,6 +54,14 @@ pub struct Spirc {
     commands: mpsc::UnboundedSender<SpircCommand>,
 }
 
+fn now_ms() -> i64 {
+    let dur = match SystemTime::now().duration_since(UNIX_EPOCH) {
+        Ok(dur) => dur,
+        Err(err) => err.duration(),
+    };
+    (dur.as_secs() * 1000 + (dur.subsec_nanos() / 1000_000) as u64) as i64
+}
+
 fn initial_state() -> State {
     protobuf_init!(protocol::spirc::State::new(), {
         repeat: false,