diff --git a/.travis.yml b/.travis.yml
index 62f185b2c..ec877eb68 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -14,6 +14,7 @@ env:
   global:
    - secure: "bG4YYWMfl9API0MSRgmOaJrlGLv06tRg9KJNawBieZvBJbITPpxVGJZT3/l/SEJ+Rl15e2dRex4k+MGQlmT2SqPQxTEYWv1qxNigKPPcla7IWeNmWWqW8uVvFjdglojgBOK2k/xErVQtA4zDfi3mwSXH4DKwquXWsoEKmX2SV7M="
    - secure: "Cbvap9ubVKgjPe3hUhI6JGeDZzBXHpOG9RaYKh+SdoIPhKnlJiNOYm1egomi+e4uqJInlFKuVHTw7Ng9Cun6Zm0jIxpkSchv1GpsR7hmB3UGnGed19Dw8121FwuUaktN+4YnbVlsyd+u8EHD3+h58t4eELrLrZolM4rS7DL6caA="
+   - secure: "RiBIBfVhhaMjU5ksuwJO3shdvG9FpinBjdSv4co9jg9171SR8edNriedHjVKSIeBhSGNmZmX+twS3dJS/By6tl/LKh9sTynA+ZAYYljkE7jn881B/gMrlYvdAA6og5KvkhV1/0iJWlhuZrMTkhpDR200iLgg3EWBhWjltzmDW/I="
 
 before_install:
 - ./scripts/setup_travis.sh
diff --git a/README.md b/README.md
index 4ca8960be..e642468a3 100644
--- a/README.md
+++ b/README.md
@@ -27,9 +27,18 @@ First off: if you hit problems during development try:
 
 This will clear cached build data and update to the latest versions of dependencies.
 
+### Mapbox API access tokens
+
+The demo applications use Mapbox vector tiles, which **require a Mapbox account and API access token**. Obtain an access token on the [Mapbox account page](https://www.mapbox.com/account/apps/). 
+
 ## OS X
 
-First run:
+in the Xcode project, click on the Target icon next to the Run/Stop button, and then "Edit Scheme". In the screen, add an environment variable with the name `MAPBOX_ACCESS_TOKEN` to the targets you want to run.
+
+![Setting the access token](https://cloud.githubusercontent.com/assets/52399/3543326/9e7cfbb8-0860-11e4-8def-3684a9028b61.png)
+
+
+Run:
 
     make setup
 
@@ -52,6 +61,8 @@ First, pull down the submodule(s):
     git submodule init
     git submodule update
 
+Insert your access token into `MBXViewController.h`. 
+
 Then run:
 
     make setup
@@ -64,6 +75,8 @@ Target devices: iPhone 4 and above (4S, 5, 5c, 5s) and iPad 2 and above (3, 4, m
 
 ## Ubuntu
 
+Set the environment variable `MAPBOX_ACCESS_TOKEN` to your token.
+
 Ensure you have git and other build essentials:
 
     sudo apt-get update
diff --git a/include/llmr/map/map.hpp b/include/llmr/map/map.hpp
index 1af6b3c54..defc1bef1 100644
--- a/include/llmr/map/map.hpp
+++ b/include/llmr/map/map.hpp
@@ -59,6 +59,8 @@ public:
     void setDefaultTransitionDuration(uint64_t duration_milliseconds = 0);
     void setStyleJSON(std::string newStyleJSON);
     std::string getStyleJSON() const;
+    void setAccessToken(std::string access_token);
+    std::string getAccessToken() const;
 
     // Transition
     void cancelTransitions();
@@ -166,6 +168,7 @@ private:
     Painter painter;
 
     std::string styleJSON = "";
+    std::string accessToken = "";
 
     bool debug = false;
     timestamp animationTime = 0;
diff --git a/include/llmr/map/source.hpp b/include/llmr/map/source.hpp
index 2937a8f69..f74624925 100644
--- a/include/llmr/map/source.hpp
+++ b/include/llmr/map/source.hpp
@@ -23,7 +23,8 @@ class Texturepool;
 class Source : public std::enable_shared_from_this<Source>, private util::noncopyable {
 public:
     Source(SourceType type = SourceType::Vector, const std::string &url = "",
-           uint32_t tile_size = 512, uint32_t min_zoom = 0, uint32_t max_zoom = 22);
+           uint32_t tile_size = 512, uint32_t min_zoom = 0, uint32_t max_zoom = 22,
+           const std::string &access_token = "");
 
     bool update(Map &map);
     void updateMatrices(const mat4 &projMatrix, const TransformState &transform);
@@ -35,7 +36,7 @@ public:
     std::forward_list<Tile::ID> getIDs() const;
     void updateClipIDs(const std::map<Tile::ID, ClipID> &mapping);
 
-    static std::string normalizeSourceURL(const std::string &url);
+    static std::string normalizeSourceURL(const std::string &url, const std::string &access_token);
 
 public:
     const SourceType type;
diff --git a/include/llmr/style/style.hpp b/include/llmr/style/style.hpp
index 37a50485b..cfaba1898 100644
--- a/include/llmr/style/style.hpp
+++ b/include/llmr/style/style.hpp
@@ -16,6 +16,7 @@
 
 namespace llmr {
 
+class Map;
 class Sprite;
 class Source;
 class StyleLayer;
@@ -27,7 +28,7 @@ public:
     struct exception : std::runtime_error { exception(const char *msg) : std::runtime_error(msg) {} };
 
 public:
-    Style();
+    Style(Map &map);
 
     void loadJSON(const uint8_t *const data);
 
@@ -63,6 +64,7 @@ private:
 
 
 private:
+    Map &map;
     std::set<std::shared_ptr<Source>> activeSources;
     PropertyTransition defaultTransition;
     bool initial_render_complete = false;
diff --git a/include/llmr/style/style_parser.hpp b/include/llmr/style/style_parser.hpp
index 10cd3d2e8..27dfd4757 100644
--- a/include/llmr/style/style_parser.hpp
+++ b/include/llmr/style/style_parser.hpp
@@ -17,6 +17,7 @@ namespace llmr {
 
 enum class ClassID : uint32_t;
 
+class Map;
 class StyleLayer;
 class StyleLayerGroup;
 
@@ -24,6 +25,8 @@ class StyleParser {
 public:
     using JSVal = const rapidjson::Value&;
 
+    StyleParser(Map &map);
+
     void parse(JSVal document);
 
     std::shared_ptr<StyleLayerGroup> getLayers() {
@@ -92,6 +95,8 @@ private:
     std::forward_list<Value> parseValues(JSVal values);
 
 private:
+    Map &map;
+
     std::unordered_map<std::string, const rapidjson::Value *> constants;
 
     std::unordered_map<std::string, const std::shared_ptr<Source>> sources;
diff --git a/ios/mapbox-gl-cocoa b/ios/mapbox-gl-cocoa
index 93615fe8a..565299b7a 160000
--- a/ios/mapbox-gl-cocoa
+++ b/ios/mapbox-gl-cocoa
@@ -1 +1 @@
-Subproject commit 93615fe8a3123332d608eaae0a9b804059bd8581
+Subproject commit 565299b7a18286802f0c49560f34b36835cf06de
diff --git a/linux/main.cpp b/linux/main.cpp
index 25898fab2..889a246c2 100644
--- a/linux/main.cpp
+++ b/linux/main.cpp
@@ -60,6 +60,14 @@ int main(int argc, char *argv[]) {
     map.setAngle(settings.angle);
     map.setDebug(settings.debug);
 
+    // Set access token if present
+    const char *token = getenv("MAPBOX_ACCESS_TOKEN");
+    if (token == nullptr) {
+        fprintf(stderr, "[WARNING] no access token set. mapbox.com tiles won't work.\n");
+    } else {
+        map.setAccessToken(std::string(token));
+    }
+
     // Load style
     map.setStyleJSON(stylejson.str());
 
diff --git a/macosx/main.mm b/macosx/main.mm
index 4c5da2f32..3b01df04e 100644
--- a/macosx/main.mm
+++ b/macosx/main.mm
@@ -13,6 +13,14 @@ int main() {
     map.setAngle(settings.angle);
     map.setDebug(settings.debug);
 
+    // Set access token if present
+    const char *token = getenv("MAPBOX_ACCESS_TOKEN");
+    if (token == nullptr) {
+        fprintf(stderr, "[WARNING] no access token set. mapbox.com tiles won't work.\n");
+    } else {
+        map.setAccessToken(std::string(token));
+    }
+
     // Load style
     NSString *path = [[NSBundle mainBundle] pathForResource:@"style.min" ofType:@"js"];
     NSString *json = [NSString stringWithContentsOfFile:path
diff --git a/src/map/map.cpp b/src/map/map.cpp
index fd13c340f..4b695fdfc 100644
--- a/src/map/map.cpp
+++ b/src/map/map.cpp
@@ -22,7 +22,7 @@ using namespace llmr;
 Map::Map(View& view)
     : view(view),
       transform(),
-      style(std::make_shared<Style>()),
+      style(std::make_shared<Style>(*this)),
       glyphAtlas(std::make_shared<GlyphAtlas>(1024, 1024)),
       spriteAtlas(std::make_shared<SpriteAtlas>(512, 512)),
       texturepool(std::make_shared<Texturepool>()),
@@ -183,6 +183,14 @@ std::string Map::getStyleJSON() const {
     return styleJSON;
 }
 
+void Map::setAccessToken( std::string access_token) {
+    accessToken.swap(access_token);
+}
+
+std::string Map::getAccessToken() const {
+    return accessToken;
+}
+
 #pragma mark - Size
 
 // Note: This function is called from another thread. Make sure you only call threadsafe functions!
diff --git a/src/map/source.cpp b/src/map/source.cpp
index 8d1593f76..9736d5da5 100644
--- a/src/map/source.cpp
+++ b/src/map/source.cpp
@@ -19,23 +19,26 @@
 namespace llmr {
 
 Source::Source(SourceType type, const std::string &url,
-               uint32_t tile_size, uint32_t min_zoom, uint32_t max_zoom)
+               uint32_t tile_size, uint32_t min_zoom, uint32_t max_zoom,
+               const std::string &access_token)
     : type(type),
-      url(normalizeSourceURL(url)),
+      url(normalizeSourceURL(url, access_token)),
       tile_size(tile_size),
       min_zoom(min_zoom),
       max_zoom(max_zoom) {}
 
-std::string Source::normalizeSourceURL(const std::string &url) {
+std::string Source::normalizeSourceURL(const std::string &url, const std::string &access_token) {
     const std::string t = "mapbox://";
     if (url.compare(0, t.length(), t) == 0) {
-        return std::string("http://api.tiles.mapbox.com/v3/") + url.substr(t.length()) + "/{z}/{x}/{y}.vector.pbf";
+        if (access_token.empty()) {
+            throw std::runtime_error("You must provide a Mapbox API access token for Mapbox tile sources");
+        }
+        return std::string("https://api.tiles.mapbox.com/v4/") + url.substr(t.length()) + "/{z}/{x}/{y}.vector.pbf?access_token=" + access_token;
     } else {
         return url;
     }
 }
 
-
 bool Source::update(Map &map) {
     if (map.getTime() > updated) {
         return updateTiles(map);
diff --git a/src/style/style.cpp b/src/style/style.cpp
index 006376172..2914489a1 100644
--- a/src/style/style.cpp
+++ b/src/style/style.cpp
@@ -1,3 +1,4 @@
+#include <llmr/map/map.hpp>
 #include <llmr/style/style.hpp>
 #include <llmr/style/style_layer_group.hpp>
 #include <llmr/style/style_parser.hpp>
@@ -12,7 +13,8 @@
 
 namespace llmr {
 
-Style::Style() {
+Style::Style(Map &map)
+    : map(map) {
 }
 
 void Style::updateSources() {
@@ -107,7 +109,7 @@ void Style::loadJSON(const uint8_t *const data) {
         throw error::style_parse(doc.GetErrorOffset(), doc.GetParseError());
     }
 
-    StyleParser parser;
+    StyleParser parser(map);
     parser.parse(const_cast<const rapidjson::Document &>(doc));
 
     layers = parser.getLayers();
diff --git a/src/style/style_parser.cpp b/src/style/style_parser.cpp
index 1821a66bd..9952a2286 100644
--- a/src/style/style_parser.cpp
+++ b/src/style/style_parser.cpp
@@ -1,3 +1,4 @@
+#include <llmr/map/map.hpp>
 #include <llmr/style/style_parser.hpp>
 #include <llmr/style/style_layer_group.hpp>
 #include <llmr/util/constants.hpp>
@@ -8,6 +9,10 @@ namespace llmr {
 
 using JSVal = const rapidjson::Value&;
 
+StyleParser::StyleParser(Map &map)
+    : map(map) {
+}
+
 void StyleParser::parse(JSVal document) {
     if (document.HasMember("constants")) {
         parseConstants(document["constants"]);
@@ -169,7 +174,7 @@ void StyleParser::parseSources(JSVal value) {
             parseRenderProperty(itr->value, min_zoom, "minZoom");
             parseRenderProperty(itr->value, max_zoom, "maxZoom");
 
-            sources.emplace(std::move(name), std::make_shared<Source>(type, url, tile_size, min_zoom, max_zoom));
+            sources.emplace(std::move(name), std::make_shared<Source>(type, url, tile_size, min_zoom, max_zoom, map.getAccessToken()));
         }
     } else {
         throw Style::exception("sources must be an object");