diff --git a/src/mbgl/style/collection.hpp b/src/mbgl/style/collection.hpp
index 91244cb71..7d67fac94 100644
--- a/src/mbgl/style/collection.hpp
+++ b/src/mbgl/style/collection.hpp
@@ -63,12 +63,12 @@ class Collection<T, false /*persistentImplsOrder*/> : public CollectionBase<T> {
 
 public:
     T* add(std::unique_ptr<T> wrapper, const optional<std::string>& before = nullopt) {
-        std::size_t index = before ? Base::index(*before) : Base::size();
-        return Base::add(index, index, std::move(wrapper));
+        std::size_t idx = before ? Base::index(*before) : Base::size();
+        return Base::add(idx, idx, std::move(wrapper));
     }
     std::unique_ptr<T> remove(const std::string& id) {
-        std::size_t index = Base::index(id);
-        return Base::remove(index, index);
+        std::size_t idx = Base::index(id);
+        return Base::remove(idx, idx);
     }
     void update(const T& wrapper) { Base::update(Base::index(wrapper.getID()), wrapper); }
 };
diff --git a/src/mbgl/style/sources/geojson_source.cpp b/src/mbgl/style/sources/geojson_source.cpp
index ea6fb5cc6..7767859b3 100644
--- a/src/mbgl/style/sources/geojson_source.cpp
+++ b/src/mbgl/style/sources/geojson_source.cpp
@@ -78,16 +78,16 @@ void GeoJSONSource::loadDescription(FileSource& fileSource) {
         } else {
             auto makeImplInBackground = [currentImpl = baseImpl, data = res.data]() -> Immutable<Source::Impl> {
                 assert(data);
-                auto& impl = static_cast<const Impl&>(*currentImpl);
+                auto& current = static_cast<const Impl&>(*currentImpl);
                 conversion::Error error;
                 std::shared_ptr<GeoJSONData> geoJSONData;
                 if (optional<GeoJSON> geoJSON = conversion::convertJSON<GeoJSON>(*data, error)) {
-                    geoJSONData = GeoJSONData::create(*geoJSON, impl.getOptions());
+                    geoJSONData = GeoJSONData::create(*geoJSON, current.getOptions());
                 } else {
                     // Create an empty GeoJSON VT object to make sure we're not infinitely waiting for tiles to load.
                     Log::Error(Event::ParseStyle, "Failed to parse GeoJSON data: %s", error.message.c_str());
                 }
-                return makeMutable<Impl>(impl, std::move(geoJSONData));
+                return makeMutable<Impl>(current, std::move(geoJSONData));
             };
             auto onImplReady = [this, self = makeWeakPtr(), capturedReq = req.get()](Immutable<Source::Impl> newImpl) {
                 assert(capturedReq);