diff --git a/src/mbgl/tile/file_based_tile_source.hpp b/src/mbgl/tile/file_based_tile_source.hpp
index ee0646961..77028e780 100644
--- a/src/mbgl/tile/file_based_tile_source.hpp
+++ b/src/mbgl/tile/file_based_tile_source.hpp
@@ -1,5 +1,6 @@
 #pragma once
 
+#include <mbgl/tile/tile_source.hpp>
 #include <mbgl/storage/resource.hpp>
 
 namespace mbgl {
@@ -8,10 +9,10 @@ class FileSource;
 class AsyncRequest;
 class Response;
 
-template <typename T, typename I>
-class FileBasedTileSource : public T {
+template <typename T>
+class FileBasedTileSource : public TileSource {
 public:
-    FileBasedTileSource(typename T::data_type&, const Resource&, FileSource&);
+    FileBasedTileSource(T&, const Resource&, FileSource&);
     virtual ~FileBasedTileSource() = default;
 
 protected:
@@ -24,6 +25,7 @@ private:
     void loadRequired();
 
 private:
+    T& tileData;
     Resource resource;
     FileSource& fileSource;
     std::unique_ptr<AsyncRequest> request;
diff --git a/src/mbgl/tile/file_based_tile_source_impl.hpp b/src/mbgl/tile/file_based_tile_source_impl.hpp
index b8a69e3f6..2d10b6458 100644
--- a/src/mbgl/tile/file_based_tile_source_impl.hpp
+++ b/src/mbgl/tile/file_based_tile_source_impl.hpp
@@ -7,11 +7,11 @@
 
 namespace mbgl {
 
-template <typename T, typename I>
-FileBasedTileSource<T, I>::FileBasedTileSource(typename T::data_type& tileData_,
-                                               const Resource& resource_,
-                                               FileSource& fileSource_)
-    : T(tileData_), resource(resource_), fileSource(fileSource_) {
+template <typename T>
+FileBasedTileSource<T>::FileBasedTileSource(T& tileData_,
+                                            const Resource& resource_,
+                                            FileSource& fileSource_)
+    : tileData(tileData_), resource(resource_), fileSource(fileSource_) {
     assert(!request);
     if (fileSource.supportsOptionalRequests()) {
         // When supported, the first request is always optional, even if the TileSource
@@ -23,7 +23,7 @@ FileBasedTileSource<T, I>::FileBasedTileSource(typename T::data_type& tileData_,
     } else {
         // When the FileSource doesn't support optional requests, we do nothing until the
         // data is definitely required.
-        if (T::isRequired()) {
+        if (isRequired()) {
             loadRequired();
         } else {
             // We're using this field to check whether the pending request is optional or required.
@@ -32,15 +32,15 @@ FileBasedTileSource<T, I>::FileBasedTileSource(typename T::data_type& tileData_,
     }
 }
 
-template <typename T, typename I>
-void FileBasedTileSource<T, I>::loadOptional() {
+template <typename T>
+void FileBasedTileSource<T>::loadOptional() {
     assert(!request);
 
     resource.necessity = Resource::Optional;
     request = fileSource.request(resource, [this](Response res) {
         request.reset();
 
-        T::tileData.setTriedOptional();
+        tileData.setTriedOptional();
 
         if (res.error && res.error->reason == Response::Error::Reason::NotFound) {
             // When the optional request could not be satisfied, don't treat it as an error.
@@ -51,31 +51,31 @@ void FileBasedTileSource<T, I>::loadOptional() {
             loadedData(res);
         }
 
-        if (T::isRequired()) {
+        if (isRequired()) {
             loadRequired();
         }
     });
 }
 
-template <typename T, typename I>
-void FileBasedTileSource<T, I>::makeRequired() {
+template <typename T>
+void FileBasedTileSource<T>::makeRequired() {
     if (!request) {
         loadRequired();
     }
 }
 
-template <typename T, typename I>
-void FileBasedTileSource<T, I>::makeOptional() {
+template <typename T>
+void FileBasedTileSource<T>::makeOptional() {
     if (resource.necessity == Resource::Required && request) {
         // Abort a potential HTTP request.
         request.reset();
     }
 }
 
-template <typename T, typename I>
-void FileBasedTileSource<T, I>::loadedData(const Response& res) {
+template <typename T>
+void FileBasedTileSource<T>::loadedData(const Response& res) {
     if (res.error && res.error->reason != Response::Error::Reason::NotFound) {
-        T::tileData.setError(std::make_exception_ptr(std::runtime_error(res.error->message)));
+        tileData.setError(std::make_exception_ptr(std::runtime_error(res.error->message)));
     } else if (res.notModified) {
         resource.priorExpires = res.expires;
         // Do not notify the TileData object; when we get this message, it already has the current
@@ -84,13 +84,13 @@ void FileBasedTileSource<T, I>::loadedData(const Response& res) {
         resource.priorModified = res.modified;
         resource.priorExpires = res.expires;
         resource.priorEtag = res.etag;
-        T::tileData.setData(res.noContent ? nullptr : I::parseData(res.data), res.modified,
+        tileData.setData(res.noContent ? nullptr : T::parseData(res.data), res.modified,
                             res.expires);
     }
 }
 
-template <typename T, typename I>
-void FileBasedTileSource<T, I>::loadRequired() {
+template <typename T>
+void FileBasedTileSource<T>::loadRequired() {
     assert(!request);
 
     resource.necessity = Resource::Required;
diff --git a/src/mbgl/tile/raster_tile_data.cpp b/src/mbgl/tile/raster_tile_data.cpp
index ac6299e22..f28da3d3d 100644
--- a/src/mbgl/tile/raster_tile_data.cpp
+++ b/src/mbgl/tile/raster_tile_data.cpp
@@ -23,7 +23,7 @@ RasterTileData::RasterTileData(const OverscaledTileID& id_,
     const auto resource = Resource::tile(
         tileset.tiles.at(0), parameters.pixelRatio, id_.canonical.x,
         id_.canonical.y, id_.canonical.z);
-    tileSource = std::make_unique<FileBasedTileSource<RasterTileSource, RasterTileData>>(
+    tileSource = std::make_unique<FileBasedTileSource<RasterTileData>>(
         *this, resource, parameters.fileSource);
 }
 
diff --git a/src/mbgl/tile/tile_source.hpp b/src/mbgl/tile/tile_source.hpp
index 8ecc9c3fa..b21da0bcd 100644
--- a/src/mbgl/tile/tile_source.hpp
+++ b/src/mbgl/tile/tile_source.hpp
@@ -57,38 +57,4 @@ protected:
     Necessity necessity;
 };
 
-class GeometryTileData;
-class RasterTileData;
-
-class GeometryTileSource : public TileSource {
-public:
-    using data_type = GeometryTileData;
-
-protected:
-    GeometryTileSource(data_type& tileData_)
-        : tileData(tileData_) {
-    }
-
-public:
-    virtual ~GeometryTileSource() = default;
-
-protected:
-    data_type& tileData;
-};
-
-class RasterTileSource : public TileSource {
-public:
-    using data_type = RasterTileData;
-
-protected:
-    RasterTileSource(data_type& tileData_)
-        : tileData(tileData_){};
-
-public:
-    virtual ~RasterTileSource() = default;
-
-protected:
-    data_type& tileData;
-};
-
 } // namespace mbgl
diff --git a/src/mbgl/tile/vector_tile_data.cpp b/src/mbgl/tile/vector_tile_data.cpp
index b9cdbc3a9..dc5c536e6 100644
--- a/src/mbgl/tile/vector_tile_data.cpp
+++ b/src/mbgl/tile/vector_tile_data.cpp
@@ -18,7 +18,7 @@ VectorTileData::VectorTileData(const OverscaledTileID& overscaledTileID,
     const auto resource = Resource::tile(
         tileset.tiles.at(0), parameters.pixelRatio, overscaledTileID.canonical.x,
         overscaledTileID.canonical.y, overscaledTileID.canonical.z);
-    tileSource = std::make_unique<FileBasedTileSource<GeometryTileSource, VectorTileData>>(
+    tileSource = std::make_unique<FileBasedTileSource<VectorTileData>>(
         *this, resource, parameters.fileSource);
 }