diff --git a/app/Album.php b/app/Album.php
index 9c5d2bc3..26858b76 100644
--- a/app/Album.php
+++ b/app/Album.php
@@ -26,10 +26,10 @@ use Illuminate\Database\Eloquent\Model;
 use Illuminate\Database\Eloquent\ModelNotFoundException;
 use Illuminate\Database\Eloquent\SoftDeletes;
 use Illuminate\Foundation\Bus\DispatchesJobs;
-use Illuminate\Support\Facades\Auth;
-use Illuminate\Support\Facades\Cache;
-use Illuminate\Support\Facades\File;
-use Illuminate\Support\Facades\URL;
+use Auth;
+use Cache;
+use File;
+use URL;
 use Poniverse\Ponyfm\Jobs\EncodeTrackFile;
 use Poniverse\Ponyfm\Traits\SlugTrait;
 
@@ -90,7 +90,7 @@ class Album extends Model
         return $this->hasMany('Poniverse\Ponyfm\Comment')->orderBy('created_at', 'desc');
     }
 
-    public static function mapPublicAlbumShow($album)
+    public static function mapPublicAlbumShow(Album $album)
     {
         $tracks = [];
         foreach ($album->tracks as $track) {
@@ -136,7 +136,7 @@ class Album extends Model
         return $data;
     }
 
-    public static function mapPublicAlbumSummary($album)
+    public static function mapPublicAlbumSummary(Album $album)
     {
         $userData = [
             'stats' => [
@@ -211,10 +211,18 @@ class Album extends Model
 
         return Cache::remember($this->getCacheKey('filesize-' . $format), 1440, function () use ($tracks, $format) {
             $size = 0;
+
             foreach ($tracks as $track) {
+                /** @var $track Track */
+
                 // Ensure that only downloadable tracks are added onto the file size
                 if ($track->is_downloadable == 1) {
-                    $size += $track->getFilesize($format);
+                    try {
+                        $size += $track->getFilesize($format);
+
+                    } catch (TrackFileNotFoundException $e) {
+                        // do nothing - this track won't be included in the download
+                    }
                 }
             }
 
@@ -260,6 +268,8 @@ class Album extends Model
         $index = 1;
 
         foreach ($tracks as $track) {
+            /** @var $track Track */
+
             $track->track_number = $index;
             $index++;
             $track->updateTags();
@@ -287,6 +297,9 @@ class Album extends Model
         $cachedCount = 0;
 
         foreach ($this->tracks as $track) {
+            /** @var $track Track */
+
+
             if ($track->is_downloadable == false) {
                 continue;
             }
@@ -308,6 +321,8 @@ class Album extends Model
     public function encodeCacheableTrackFiles($format)
     {
         foreach ($this->tracks as $track) {
+            /** @var $track Track */
+
             if ($track->is_downloadable == false) {
                 continue;
             }
@@ -363,7 +378,9 @@ class Album extends Model
                 continue;
             }
 
+            /** @var $track Track */
             $track = Track::find($trackId);
+
             if ($track->album_id != null && $track->album_id != $this->id) {
                 $albumsToFix[] = $track->album;
             }
@@ -378,6 +395,8 @@ class Album extends Model
         }
 
         foreach ($tracksToRemove as $track) {
+            /** @var $track Track */
+
             $track->album_id = null;
             $track->track_number = null;
             $track->updateTags();
@@ -385,6 +404,8 @@ class Album extends Model
         }
 
         foreach ($albumsToFix as $album) {
+            /** @var $album Album */
+
             $album->updateTrackNumbers();
         }
 
diff --git a/app/Exceptions.php b/app/Exceptions.php
new file mode 100644
index 00000000..94afa01b
--- /dev/null
+++ b/app/Exceptions.php
@@ -0,0 +1,14 @@
+<?php namespace Poniverse\Ponyfm;
+
+use Illuminate\Database\Eloquent\ModelNotFoundException;
+
+/**
+ * Class TrackFileNotFoundException
+ * @package Poniverse\Ponyfm
+ *
+ * This exception is used to indicate that the requested `TrackFile` object
+ * does not exist. This is useful when dealing with albums or playlists that
+ * contain tracks for which no lossless master is available (and thus, lossless
+ * `TrackFiles` don't exist for).
+ */
+class TrackFileNotFoundException extends ModelNotFoundException {}
diff --git a/app/Playlist.php b/app/Playlist.php
index 8d8ac4ec..e68eb981 100644
--- a/app/Playlist.php
+++ b/app/Playlist.php
@@ -26,9 +26,9 @@ use Illuminate\Database\Eloquent\Model;
 use Illuminate\Database\Eloquent\ModelNotFoundException;
 use Illuminate\Database\Eloquent\SoftDeletes;
 use Illuminate\Foundation\Bus\DispatchesJobs;
-use Illuminate\Support\Facades\Auth;
-use Illuminate\Support\Facades\Cache;
-use Illuminate\Support\Facades\URL;
+use Auth;
+use Cache;
+use URL;
 use Poniverse\Ponyfm\Jobs\EncodeTrackFile;
 use Poniverse\Ponyfm\Traits\SlugTrait;
 
@@ -59,10 +59,12 @@ class Playlist extends Model
         return !$query;
     }
 
-    public static function mapPublicPlaylistShow($playlist)
+    public static function mapPublicPlaylistShow(Playlist $playlist)
     {
         $tracks = [];
         foreach ($playlist->tracks as $track) {
+            /** @var $track Track */
+
             $tracks[] = Track::mapPublicTrackSummary($track);
         }
 
@@ -95,7 +97,7 @@ class Playlist extends Model
         return $data;
     }
 
-    public static function mapPublicPlaylistSummary($playlist)
+    public static function mapPublicPlaylistSummary(Playlist $playlist)
     {
         $userData = [
             'stats' => [
@@ -222,6 +224,8 @@ class Playlist extends Model
         $cachedCount = 0;
 
         foreach ($this->tracks as $track) {
+            /** @var $track Track */
+
             if ($track->is_downloadable == false) {
                 continue;
             }
@@ -239,6 +243,8 @@ class Playlist extends Model
     public function encodeCacheableTrackFiles($format)
     {
         foreach ($this->tracks as $track) {
+            /** @var $track Track */
+
             if ($track->is_downloadable == false) {
                 continue;
             }
@@ -265,9 +271,16 @@ class Playlist extends Model
         return Cache::remember($this->getCacheKey('filesize-' . $format), 1440, function () use ($tracks, $format) {
             $size = 0;
             foreach ($tracks as $track) {
+                /** @var $track Track */
+
                 // Ensure that only downloadable tracks are added onto the file size
                 if ($track->is_downloadable == 1) {
-                    $size += $track->getFilesize($format);
+                    try {
+                        $size += $track->getFilesize($format);
+
+                    } catch (TrackFileNotFoundException $e) {
+                        // do nothing - this track won't be included in the download
+                    }
                 }
             }
 
diff --git a/app/Track.php b/app/Track.php
index 7afa25b5..09604f20 100644
--- a/app/Track.php
+++ b/app/Track.php
@@ -24,6 +24,7 @@ use Auth;
 use Cache;
 use Config;
 use DB;
+use Illuminate\Database\Eloquent\ModelNotFoundException;
 use Poniverse\Ponyfm\Traits\SlugTrait;
 use Exception;
 use External;
@@ -214,7 +215,7 @@ class Track extends Model
         return $processed;
     }
 
-    public static function mapPublicTrackShow($track)
+    public static function mapPublicTrackShow(Track $track)
     {
         $returnValue = self::mapPublicTrackSummary($track);
         $returnValue['description'] = $track->description;
@@ -261,7 +262,7 @@ class Track extends Model
         return $returnValue;
     }
 
-    public static function mapPublicTrackSummary($track)
+    public static function mapPublicTrackSummary(Track $track)
     {
         $userData = [
             'stats' => [
@@ -333,7 +334,7 @@ class Track extends Model
         ];
     }
 
-    public static function mapPrivateTrackShow($track)
+    public static function mapPrivateTrackShow(Track $track)
     {
         $showSongs = [];
         foreach ($track->showSongs as $showSong) {
@@ -354,7 +355,7 @@ class Track extends Model
         return $returnValue;
     }
 
-    public static function mapPrivateTrackSummary($track)
+    public static function mapPrivateTrackSummary(Track $track)
     {
         return [
             'id' => $track->id,
@@ -438,9 +439,22 @@ class Track extends Model
         $this->updateHash();
     }
 
+    /**
+     * Returns the size of this track's file in the given format.
+     *
+     * @param $formatName
+     * @return int filesize in bytes
+     * @throws TrackFileNotFoundException
+     */
     public function getFilesize($formatName)
     {
-        return $this->trackFiles()->where('format', $formatName)->first()->filesize;
+        $trackFile = $this->trackFiles()->where('format', $formatName)->first();
+
+        if ($trackFile) {
+            return (int) $trackFile->filesize;
+        } else {
+            throw new TrackFileNotFoundException();
+        }
     }
 
     public function canView($user)
diff --git a/app/TrackFile.php b/app/TrackFile.php
index d7a35855..46c67190 100644
--- a/app/TrackFile.php
+++ b/app/TrackFile.php
@@ -22,10 +22,9 @@ namespace Poniverse\Ponyfm;
 
 use Helpers;
 use Illuminate\Database\Eloquent\Model;
-use Illuminate\Support\Facades\App;
-use Illuminate\Support\Facades\Cache;
-use Illuminate\Support\Facades\File;
-use Illuminate\Support\Facades\URL;
+use App;
+use File;
+use URL;
 
 class TrackFile extends Model
 {
@@ -85,9 +84,9 @@ class TrackFile extends Model
         return URL::to('/t' . $this->track_id . '/dl.' . $this->extension);
     }
 
-    public function getSizeAttribute($value)
+    public function getSizeAttribute()
     {
-        return Helpers::formatBytes($this->getFilesize($this->getFile()));
+        return Helpers::formatBytes($this->getFilesize());
     }
 
     public function getFormat()
diff --git a/database/migrations/2015_10_26_192855_update_track_files_with_cache.php b/database/migrations/2015_10_26_192855_update_track_files_with_cache.php
index 5e8c1b0d..5352f319 100644
--- a/database/migrations/2015_10_26_192855_update_track_files_with_cache.php
+++ b/database/migrations/2015_10_26_192855_update_track_files_with_cache.php
@@ -46,8 +46,8 @@ class UpdateTrackFilesWithCache extends Migration
     {
         Schema::table('track_files', function (Blueprint $table) {
             $table->dropColumn('is_cacheable');
-            $table->dropColumn('expiration');
-            $table->dropColumn('in_progress');
+            $table->dropColumn('expires_at');
+            $table->dropColumn('is_in_progress');
         });
     }
 }