diff --git a/platform/default/mbgl/storage/offline_download.cpp b/platform/default/mbgl/storage/offline_download.cpp
index 04aabeb04..8a156dd64 100644
--- a/platform/default/mbgl/storage/offline_download.cpp
+++ b/platform/default/mbgl/storage/offline_download.cpp
@@ -108,13 +108,13 @@ OfflineRegionStatus OfflineDownload::getStatus() const {
         case SourceType::Raster: {
             style::TileSource* tileSource = static_cast<style::TileSource*>(source.get());
             if (tileSource->getTileset()) {
-                result.requiredResourceCount += tileResources(source->type, source->tileSize, *tileSource->getTileset()).size();
+                result.requiredResourceCount += tileResources(source->type, tileSource->getTileSize(), *tileSource->getTileset()).size();
             } else {
                 result.requiredResourceCount += 1;
                 optional<Response> sourceResponse = offlineDatabase.get(Resource::source(tileSource->getURL()));
                 if (sourceResponse) {
-                    result.requiredResourceCount += tileResources(source->type, source->tileSize,
-                        *style::parseTileJSON(*sourceResponse->data, tileSource->getURL(), source->type, source->tileSize)).size();
+                    result.requiredResourceCount += tileResources(source->type, tileSource->getTileSize(),
+                        *style::parseTileJSON(*sourceResponse->data, tileSource->getURL(), source->type, tileSource->getTileSize())).size();
                 } else {
                     result.requiredResourceCountIsPrecise = false;
                 }
@@ -156,12 +156,12 @@ void OfflineDownload::activateDownload() {
 
         for (const auto& source : parser.sources) {
             SourceType type = source->type;
-            uint16_t tileSize = source->tileSize;
 
             switch (type) {
             case SourceType::Vector:
             case SourceType::Raster: {
-                style::TileSource* tileSource = static_cast<style::TileSource*>(source.get());
+                const style::TileSource* tileSource = static_cast<style::TileSource*>(source.get());
+                const uint16_t tileSize = tileSource->getTileSize();
                 if (tileSource->getTileset()) {
                     ensureTiles(type, tileSize, *tileSource->getTileset());
                 } else {
diff --git a/src/mbgl/annotation/annotation_source.cpp b/src/mbgl/annotation/annotation_source.cpp
index 637109ff8..2c87c4f20 100644
--- a/src/mbgl/annotation/annotation_source.cpp
+++ b/src/mbgl/annotation/annotation_source.cpp
@@ -5,7 +5,7 @@
 namespace mbgl {
 
 AnnotationSource::AnnotationSource()
-    : Source(SourceType::Annotations, AnnotationManager::SourceID, util::tileSize) {
+    : Source(SourceType::Annotations, AnnotationManager::SourceID) {
 }
 
 Range<uint8_t> AnnotationSource::getZoomRange() {
diff --git a/src/mbgl/annotation/annotation_source.hpp b/src/mbgl/annotation/annotation_source.hpp
index 830be519c..e8d3b43e0 100644
--- a/src/mbgl/annotation/annotation_source.hpp
+++ b/src/mbgl/annotation/annotation_source.hpp
@@ -11,7 +11,9 @@ public:
     void load(FileSource&) final;
 
 private:
+    uint16_t getTileSize() const final { return util::tileSize; }
     Range<uint8_t> getZoomRange() final;
+
     std::unique_ptr<Tile> createTile(const OverscaledTileID&, const style::UpdateParameters&) final;
 };
 
diff --git a/src/mbgl/style/source.cpp b/src/mbgl/style/source.cpp
index 21fb7fee3..ca0943918 100644
--- a/src/mbgl/style/source.cpp
+++ b/src/mbgl/style/source.cpp
@@ -32,10 +32,9 @@ namespace style {
 
 static SourceObserver nullObserver;
 
-Source::Source(SourceType type_, std::string id_, uint16_t tileSize_)
+Source::Source(SourceType type_, std::string id_)
     : type(type_),
       id(std::move(id_)),
-      tileSize(tileSize_),
       observer(&nullObserver) {
 }
 
@@ -94,6 +93,7 @@ bool Source::update(const UpdateParameters& parameters) {
         return allTilesUpdated;
     }
 
+    const uint16_t tileSize = getTileSize();
     const Range<uint8_t> zoomRange = getZoomRange();
 
     // Determine the overzooming/underzooming amounts and required tiles.
diff --git a/src/mbgl/style/source.hpp b/src/mbgl/style/source.hpp
index 99d634a88..575297e32 100644
--- a/src/mbgl/style/source.hpp
+++ b/src/mbgl/style/source.hpp
@@ -32,7 +32,7 @@ class SourceObserver;
 
 class Source : public TileObserver, private util::noncopyable {
 public:
-    Source(SourceType, std::string id, uint16_t tileSize);
+    Source(SourceType, std::string id);
     ~Source() override;
 
     bool loaded = false;
@@ -68,7 +68,6 @@ public:
 
     const SourceType type;
     const std::string id;
-    uint16_t tileSize = util::tileSize;
     bool enabled = false;
 
 private:
@@ -77,6 +76,7 @@ private:
     void onTileError(Tile&, std::exception_ptr) override;
     void onNeedsRepaint() override;
 
+    virtual uint16_t getTileSize() const = 0;
     virtual Range<uint8_t> getZoomRange() = 0;
     virtual std::unique_ptr<Tile> createTile(const OverscaledTileID&, const UpdateParameters&) = 0;
 
diff --git a/src/mbgl/style/sources/geojson_source.cpp b/src/mbgl/style/sources/geojson_source.cpp
index 7daf14829..01089f2ee 100644
--- a/src/mbgl/style/sources/geojson_source.cpp
+++ b/src/mbgl/style/sources/geojson_source.cpp
@@ -63,7 +63,7 @@ std::unique_ptr<GeoJSONSource> GeoJSONSource::parse(const std::string& id,
 GeoJSONSource::GeoJSONSource(std::string id_,
                              std::string url_,
                              std::unique_ptr<mapbox::geojsonvt::GeoJSONVT>&& geojsonvt_)
-    : Source(SourceType::GeoJSON, std::move(id_), util::tileSize),
+    : Source(SourceType::GeoJSON, std::move(id_)),
       url(url_),
       geojsonvt(std::move(geojsonvt_)) {
 }
diff --git a/src/mbgl/style/sources/geojson_source.hpp b/src/mbgl/style/sources/geojson_source.hpp
index 996dac3ac..00d245c87 100644
--- a/src/mbgl/style/sources/geojson_source.hpp
+++ b/src/mbgl/style/sources/geojson_source.hpp
@@ -31,6 +31,7 @@ public:
     const std::string& getURL() const { return url; }
 
 private:
+    uint16_t getTileSize() const final { return util::tileSize; }
     Range<uint8_t> getZoomRange() final;
     std::unique_ptr<Tile> createTile(const OverscaledTileID&, const UpdateParameters&) final;
 
diff --git a/src/mbgl/style/tile_source.cpp b/src/mbgl/style/tile_source.cpp
index 29cbcc722..a4deb17c4 100644
--- a/src/mbgl/style/tile_source.cpp
+++ b/src/mbgl/style/tile_source.cpp
@@ -12,7 +12,8 @@ TileSource::TileSource(SourceType type_,
                        std::string url_,
                        uint16_t tileSize_,
                        std::unique_ptr<Tileset>&& tileset_)
-    : Source(type_, std::move(id_), tileSize_),
+    : Source(type_, std::move(id_)),
+      tileSize(tileSize_),
       url(std::move(url_)),
       tileset(std::move(tileset_)) {
 }
diff --git a/src/mbgl/style/tile_source.hpp b/src/mbgl/style/tile_source.hpp
index b001d174f..bc97713a0 100644
--- a/src/mbgl/style/tile_source.hpp
+++ b/src/mbgl/style/tile_source.hpp
@@ -25,11 +25,13 @@ public:
     void load(FileSource&) final;
 
     const std::string& getURL() const { return url; }
+    uint16_t getTileSize() const final { return tileSize; }
     const Tileset* getTileset() const { return tileset.get(); }
 
 protected:
     Range<uint8_t> getZoomRange() final;
 
+    const uint16_t tileSize;
     const std::string url;
     std::unique_ptr<const Tileset> tileset;
     std::unique_ptr<AsyncRequest> req;