diff --git a/gyp/mbgl-headless.gypi b/gyp/mbgl-headless.gypi
index 08ac21181..da11c8781 100644
--- a/gyp/mbgl-headless.gypi
+++ b/gyp/mbgl-headless.gypi
@@ -4,12 +4,32 @@
       'product_name': 'mbgl-headless',
       'type': 'static_library',
       'standalone_static_library': 1,
+      'variables': {
+        'cflags_cc': [
+          '<@(uv_cflags)',
+        ],
+        'cflags': [
+          '<@(uv_cflags)',
+        ],
+      },
       'include_dirs': [
         '../include',
       ],
+      'conditions': [
+        ['OS == "mac"', {
+          'xcode_settings': {
+            'OTHER_CPLUSPLUSFLAGS': [ '<@(cflags_cc)' ],
+            'OTHER_CFLAGS': [ '<@(cflags)' ],
+          }
+        }, {
+          'cflags_cc': [ '<@(cflags_cc)' ],
+          'cflags': [ '<@(cflags)' ],
+        }]
+      ],
       'sources': [
         '../platform/default/headless_view.cpp',
         '../platform/default/headless_display.cpp',
+        '../platform/default/caching_http_file_source.cpp',
       ],
     },
   ],
diff --git a/gyp/mbgl-ios.gypi b/gyp/mbgl-ios.gypi
index c2cb2eed5..a2e6f65ba 100644
--- a/gyp/mbgl-ios.gypi
+++ b/gyp/mbgl-ios.gypi
@@ -36,6 +36,7 @@
         '../platform/darwin/string_nsstring.mm',
         '../platform/darwin/http_request_baton_cocoa.mm',
         '../platform/darwin/image.mm',
+        '../platform/default/caching_http_file_source.cpp',
         '../platform/default/asset_request_baton_noop.cpp',
       ],
       'include_dirs': [
diff --git a/gyp/mbgl-linux.gypi b/gyp/mbgl-linux.gypi
index 5bfa8f757..2f402075a 100644
--- a/gyp/mbgl-linux.gypi
+++ b/gyp/mbgl-linux.gypi
@@ -35,6 +35,7 @@
         '../platform/default/image_reader.cpp',
         '../platform/default/png_reader.cpp',
         '../platform/default/jpeg_reader.cpp',
+        '../platform/default/caching_http_file_source.cpp',
         '../platform/default/asset_request_baton_noop.cpp',
       ],
       'include_dirs': [
diff --git a/gyp/mbgl-osx.gypi b/gyp/mbgl-osx.gypi
index 0ca00a81e..d0eae5673 100644
--- a/gyp/mbgl-osx.gypi
+++ b/gyp/mbgl-osx.gypi
@@ -11,6 +11,7 @@
         '../platform/darwin/string_nsstring.mm',
         '../platform/darwin/http_request_baton_cocoa.mm',
         '../platform/darwin/image.mm',
+        '../platform/default/caching_http_file_source.cpp',
         '../platform/default/asset_request_baton_noop.cpp',
       ],
       'include_dirs': [
diff --git a/include/mbgl/map/map.hpp b/include/mbgl/map/map.hpp
index 2f81a2bd8..f222036bf 100644
--- a/include/mbgl/map/map.hpp
+++ b/include/mbgl/map/map.hpp
@@ -34,7 +34,7 @@ class Map : private util::noncopyable {
     typedef void (*stop_callback)(void *);
 
 public:
-    explicit Map(View &view);
+    explicit Map(View&, FileSource&);
     ~Map();
 
     // Start the map render thread. It is asynchronous.
@@ -197,7 +197,7 @@ private:
     Transform transform;
     TransformState state;
 
-    util::ptr<FileSource> fileSource;
+    FileSource& fileSource;
 
     util::ptr<Style> style;
     GlyphAtlas glyphAtlas;
diff --git a/include/mbgl/platform/default/caching_http_file_source.hpp b/include/mbgl/platform/default/caching_http_file_source.hpp
new file mode 100644
index 000000000..058bdc7c3
--- /dev/null
+++ b/include/mbgl/platform/default/caching_http_file_source.hpp
@@ -0,0 +1,52 @@
+#ifndef MBGL_STORAGE_CACHING_HTTP_FILE_SOURCE
+#define MBGL_STORAGE_CACHING_HTTP_FILE_SOURCE
+
+#include <mbgl/storage/file_source.hpp>
+
+#include <unordered_map>
+
+typedef struct uv_messenger_s uv_messenger_t;
+
+namespace mbgl {
+
+class BaseRequest;
+class SQLiteStore;
+
+class CachingHTTPFileSource : public FileSource {
+public:
+    CachingHTTPFileSource(uv_loop_t*, const std::string &path_);
+    CachingHTTPFileSource(const std::string &path_);
+    ~CachingHTTPFileSource();
+
+    // Stores and checks the libuv loop for requests
+    void setLoop(uv_loop_t*);
+    bool hasLoop();
+
+    // Stores and retrieves the base path/URL for relative requests
+    void setBase(const std::string &value);
+    const std::string &getBase() const;
+
+    std::unique_ptr<Request> request(ResourceType type, const std::string &url);
+
+    void prepare(std::function<void()> fn);
+
+    void retryAllPending();
+
+private:
+    unsigned long thread_id;
+
+    // Path to the cache database.
+    std::string path;
+
+    // Stores a URL that is used as a base for loading resources with relative path.
+    std::string base;
+
+    std::unordered_map<std::string, std::weak_ptr<BaseRequest>> pending;
+    util::ptr<SQLiteStore> store;
+    uv_loop_t *loop = nullptr;
+    uv_messenger_t *queue = nullptr;
+};
+
+}
+
+#endif
diff --git a/include/mbgl/storage/file_source.hpp b/include/mbgl/storage/file_source.hpp
index 3839ae22e..9c5182397 100644
--- a/include/mbgl/storage/file_source.hpp
+++ b/include/mbgl/storage/file_source.hpp
@@ -1,48 +1,25 @@
 #ifndef MBGL_STORAGE_FILE_SOURCE
 #define MBGL_STORAGE_FILE_SOURCE
 
+#include <mbgl/util/noncopyable.hpp>
 #include <mbgl/storage/resource_type.hpp>
 #include <mbgl/storage/request.hpp>
-#include <mbgl/util/noncopyable.hpp>
 
 #include <string>
-#include <unordered_map>
 #include <functional>
 
 typedef struct uv_loop_s uv_loop_t;
-typedef struct uv_messenger_s uv_messenger_t;
 
 namespace mbgl {
 
-class BaseRequest;
-class SQLiteStore;
-
 class FileSource : public util::noncopyable {
-private:
 public:
-    FileSource(uv_loop_t *loop, const std::string &path);
-    ~FileSource();
-
-    // Stores and retrieves the base path/URL for relative requests
-    void setBase(const std::string &value);
-    const std::string &getBase() const;
-
-    std::unique_ptr<Request> request(ResourceType type, const std::string &url);
-
-    void prepare(std::function<void()> fn);
-
-    void retryAllPending();
-
-private:
-    const unsigned long thread_id;
-
-    // Stores a URL that is used as a base for loading resources with relative path.
-    std::string base;
-
-    std::unordered_map<std::string, std::weak_ptr<BaseRequest>> pending;
-    util::ptr<SQLiteStore> store;
-    uv_loop_t *loop = nullptr;
-    uv_messenger_t *queue = nullptr;
+    virtual void setLoop(uv_loop_t*) = 0;
+    virtual bool hasLoop() = 0;
+    virtual void setBase(const std::string &value) = 0;
+    virtual std::unique_ptr<Request> request(ResourceType type, const std::string &url) = 0;
+    virtual void prepare(std::function<void()> fn) = 0;
+    virtual void retryAllPending() = 0;
 };
 
 }
diff --git a/linux/main.cpp b/linux/main.cpp
index c49957349..9cf23df95 100644
--- a/linux/main.cpp
+++ b/linux/main.cpp
@@ -4,6 +4,7 @@
 #include <mbgl/platform/default/settings_json.hpp>
 #include <mbgl/platform/default/glfw_view.hpp>
 #include <mbgl/platform/default/log_stderr.hpp>
+#include <mbgl/platform/default/caching_http_file_source.hpp>
 
 #include <signal.h>
 #include <getopt.h>
@@ -63,7 +64,8 @@ int main(int argc, char *argv[]) {
     sigaction(SIGINT, &sigIntHandler, NULL);
 
     view = new GLFWView();
-    mbgl::Map map(*view);
+    mbgl::CachingHTTPFileSource fileSource(mbgl::platform::defaultCacheDatabase());
+    mbgl::Map map(*view, fileSource);
 
     // Load settings
     mbgl::Settings_JSON settings;
diff --git a/macosx/main.mm b/macosx/main.mm
index 9a6e52757..fe654e1f7 100644
--- a/macosx/main.mm
+++ b/macosx/main.mm
@@ -2,6 +2,7 @@
 #include <mbgl/platform/darwin/log_nslog.hpp>
 #include <mbgl/platform/darwin/Reachability.h>
 #include <mbgl/platform/default/glfw_view.hpp>
+#include <mbgl/platform/default/caching_http_file_source.hpp>
 
 #import <Foundation/Foundation.h>
 
@@ -72,7 +73,8 @@ int main() {
     mbgl::Log::Set<mbgl::NSLogBackend>();
 
     GLFWView view;
-    mbgl::Map map(view);
+    mbgl::CachingHTTPFileSource fileSource(mbgl::platform::defaultCacheDatabase());
+    mbgl::Map map(view, fileSource);
     mbgl::Map *map_ptr = &map;
 
     URLHandler *handler = [[URLHandler alloc] init];
diff --git a/src/storage/file_source.cpp b/platform/default/caching_http_file_source.cpp
similarity index 57%
rename from src/storage/file_source.cpp
rename to platform/default/caching_http_file_source.cpp
index 7c1ffc47f..b7cbb268f 100644
--- a/src/storage/file_source.cpp
+++ b/platform/default/caching_http_file_source.cpp
@@ -1,4 +1,4 @@
-#include <mbgl/storage/file_source.hpp>
+#include <mbgl/platform/default/caching_http_file_source.hpp>
 #include <mbgl/storage/file_request.hpp>
 #include <mbgl/storage/http_request.hpp>
 #include <mbgl/storage/sqlite_store.hpp>
@@ -10,8 +10,9 @@
 
 namespace mbgl {
 
-FileSource::FileSource(uv_loop_t *loop_, const std::string &path)
+CachingHTTPFileSource::CachingHTTPFileSource(uv_loop_t* loop_, const std::string &path_)
     : thread_id(uv_thread_self()),
+      path(path_),
       store(!path.empty() ? util::ptr<SQLiteStore>(new SQLiteStore(loop_, path)) : nullptr),
       loop(loop_),
       queue(new uv_messenger_t) {
@@ -23,34 +24,56 @@ FileSource::FileSource(uv_loop_t *loop_, const std::string &path)
     uv_unref((uv_handle_t *)&queue->async);
 }
 
-FileSource::~FileSource() {
-    // FIXME temp fix for #608 crash
-    //assert(thread_id == uv_thread_self());
-    uv_messenger_stop(queue, [](uv_messenger_t *msgr) {
-        delete msgr;
-    });
+CachingHTTPFileSource::CachingHTTPFileSource(const std::string &path_)
+    : path(path_) {}
 
-    util::ptr<BaseRequest> req;
+CachingHTTPFileSource::~CachingHTTPFileSource() {
+    if (hasLoop()) {
+        // FIXME temp fix for #608 crash
+        // assert(thread_id == uv_thread_self());
+        uv_messenger_stop(queue, [](uv_messenger_t *msgr) {
+            delete msgr;
+        });
 
-    // Send a cancel() message to all requests that we are still holding.
-    for (const std::pair<std::string, std::weak_ptr<BaseRequest>> &pair : pending) {
-        if ((req = pair.second.lock())) {
-            req->cancel();
+        util::ptr<BaseRequest> req;
+
+        // Send a cancel() message to all requests that we are still holding.
+        for (const std::pair<std::string, std::weak_ptr<BaseRequest>> &pair : pending) {
+            if ((req = pair.second.lock())) {
+                req->cancel();
+            }
         }
     }
 }
 
-void FileSource::setBase(const std::string &value) {
+void CachingHTTPFileSource::setLoop(uv_loop_t* loop_) {
+    thread_id = uv_thread_self();
+    store = !path.empty() ? util::ptr<SQLiteStore>(new SQLiteStore(loop_, path)) : nullptr;
+    loop = loop_;
+    queue = new uv_messenger_t;
+
+    uv_messenger_init(loop, queue, [](void *ptr) {
+        std::unique_ptr<std::function<void()>> fn { reinterpret_cast<std::function<void()> *>(ptr) };
+        (*fn)();
+    });
+    uv_unref((uv_handle_t *)&queue->async);
+}
+
+bool CachingHTTPFileSource::hasLoop() {
+    return loop;
+}
+
+void CachingHTTPFileSource::setBase(const std::string &value) {
     assert(thread_id == uv_thread_self());
     base = value;
 }
 
-const std::string &FileSource::getBase() const {
+const std::string &CachingHTTPFileSource::getBase() const {
     assert(thread_id == uv_thread_self());
     return base;
 }
 
-std::unique_ptr<Request> FileSource::request(ResourceType type, const std::string &url) {
+std::unique_ptr<Request> CachingHTTPFileSource::request(ResourceType type, const std::string &url) {
     assert(thread_id == uv_thread_self());
 
     // Make URL absolute.
@@ -87,7 +110,7 @@ std::unique_ptr<Request> FileSource::request(ResourceType type, const std::strin
     return util::make_unique<Request>(req);
 }
 
-void FileSource::prepare(std::function<void()> fn) {
+void CachingHTTPFileSource::prepare(std::function<void()> fn) {
     if (thread_id == uv_thread_self()) {
         fn();
     } else {
@@ -95,7 +118,7 @@ void FileSource::prepare(std::function<void()> fn) {
     }
 }
 
-void FileSource::retryAllPending() {
+void CachingHTTPFileSource::retryAllPending() {
     assert(thread_id == uv_thread_self());
 
     util::ptr<BaseRequest> req;
diff --git a/src/map/map.cpp b/src/map/map.cpp
index 3fe770e8e..9236c5d2e 100644
--- a/src/map/map.cpp
+++ b/src/map/map.cpp
@@ -90,13 +90,14 @@ const static bool sqlite_version_check = []() {
 
 using namespace mbgl;
 
-Map::Map(View& view_)
+Map::Map(View& view_, FileSource& fileSource_)
     : loop(util::make_unique<uv::loop>()),
       view(view_),
 #ifndef NDEBUG
       mainThread(uv_thread_self()),
 #endif
       transform(view_),
+      fileSource(fileSource_),
       glyphAtlas(1024, 1024),
       spriteAtlas(512, 512),
       texturePool(std::make_shared<TexturePool>()),
@@ -120,7 +121,6 @@ Map::~Map() {
     glyphStore.reset();
     style.reset();
     texturePool.reset();
-    fileSource.reset();
     workers.reset();
 
     uv_run(**loop, UV_RUN_DEFAULT);
@@ -150,7 +150,6 @@ void Map::start(bool startPaused) {
 
         // Remove all of these to make sure they are destructed in the correct thread.
         glyphStore.reset();
-        fileSource.reset();
         style.reset();
         workers.reset();
         activeSources.clear();
@@ -371,11 +370,9 @@ void Map::terminate() {
 void Map::setReachability(bool reachable) {
     // Note: This function may be called from *any* thread.
     if (reachable) {
-        if (fileSource) {
-            fileSource->prepare([&]() {
-                fileSource->retryAllPending();
-            });
-        }
+        fileSource.prepare([&]() {
+            fileSource.retryAllPending();
+        });
     }
 }
 
@@ -407,11 +404,11 @@ void Map::setStyleJSON(std::string newStyleJSON, const std::string &base) {
     }
 
     style->loadJSON((const uint8_t *)styleJSON.c_str());
-    if (!fileSource) {
-        fileSource = std::make_shared<FileSource>(**loop, platform::defaultCacheDatabase());
-        glyphStore = std::make_shared<GlyphStore>(*fileSource);
+    if (!fileSource.hasLoop()) {
+        fileSource.setLoop(**loop);
+        glyphStore = std::make_shared<GlyphStore>(fileSource);
     }
-    fileSource->setBase(base);
+    fileSource.setBase(base);
     glyphStore->setURL(util::mapbox::normalizeGlyphsURL(style->glyph_url, getAccessToken()));
 
     style->setDefaultTransitionDuration(defaultTransitionDuration);
@@ -447,7 +444,7 @@ util::ptr<Sprite> Map::getSprite() {
     const float pixelRatio = state.getPixelRatio();
     const std::string &sprite_url = style->getSpriteURL();
     if (!sprite || sprite->pixelRatio != pixelRatio) {
-        sprite = Sprite::Create(sprite_url, pixelRatio, *fileSource);
+        sprite = Sprite::Create(sprite_url, pixelRatio, fileSource);
     }
 
     return sprite;
@@ -671,7 +668,7 @@ void Map::updateSources() {
         if (source->enabled) {
             if (!source->source) {
                 source->source = std::make_shared<Source>(source->info);
-                source->source->load(*this, *fileSource);
+                source->source->load(*this, fileSource);
             }
         } else {
             source->source.reset();
@@ -705,20 +702,20 @@ void Map::updateTiles() {
         source->source->update(*this, getWorker(),
                                style, glyphAtlas, *glyphStore,
                                spriteAtlas, getSprite(),
-                               *texturePool, *fileSource, [this](){ update(); });
+                               *texturePool, fileSource, [this](){ update(); });
     }
 }
 
 void Map::prepare() {
-    if (!fileSource) {
-        fileSource = std::make_shared<FileSource>(**loop, platform::defaultCacheDatabase());
-        glyphStore = std::make_shared<GlyphStore>(*fileSource);
+    if (!fileSource.hasLoop()) {
+        fileSource.setLoop(**loop);
+        glyphStore = std::make_shared<GlyphStore>(fileSource);
     }
 
     if (!style) {
         style = std::make_shared<Style>();
 
-        fileSource->request(ResourceType::JSON, styleURL)->onload([&](const Response &res) {
+        fileSource.request(ResourceType::JSON, styleURL)->onload([&](const Response &res) {
             if (res.code == 200) {
                 // Calculate the base
                 const size_t pos = styleURL.rfind('/');
diff --git a/test/headless.cpp b/test/headless.cpp
index e0409c473..29db9500d 100644
--- a/test/headless.cpp
+++ b/test/headless.cpp
@@ -11,6 +11,7 @@
 
 #include <mbgl/platform/default/headless_view.hpp>
 #include <mbgl/platform/default/headless_display.hpp>
+#include <mbgl/platform/default/caching_http_file_source.hpp>
 
 #include "./fixtures/fixture_log.hpp"
 
@@ -184,7 +185,8 @@ TEST_P(HeadlessTest, render) {
         }
 
         HeadlessView view(env->display);
-        Map map(view);
+        CachingHTTPFileSource fileSource(platform::defaultCacheDatabase());
+        Map map(view, fileSource);
 
         map.setStyleJSON(style, base_directory);
         map.setAppliedClasses(classes);