diff --git a/include/mbgl/style/sources/geojson_source.hpp b/include/mbgl/style/sources/geojson_source.hpp
index e633e6efb..ede030172 100644
--- a/include/mbgl/style/sources/geojson_source.hpp
+++ b/include/mbgl/style/sources/geojson_source.hpp
@@ -43,7 +43,7 @@ public:
     void setURL(const std::string& url);
     void setGeoJSON(const GeoJSON&);
 
-    optional<std::string> getURL();
+    optional<std::string> getURL() const;
 
     // Private implementation
 
diff --git a/include/mbgl/style/sources/raster_source.hpp b/include/mbgl/style/sources/raster_source.hpp
index 9bb951992..395f25e51 100644
--- a/include/mbgl/style/sources/raster_source.hpp
+++ b/include/mbgl/style/sources/raster_source.hpp
@@ -11,9 +11,12 @@ class RasterSource : public Source {
 public:
     RasterSource(std::string id, variant<std::string, Tileset> urlOrTileset, uint16_t tileSize);
 
+    optional<std::string> getURL() const;
+
     // Private implementation
 
     class Impl;
+    Impl* const impl;
 };
 
 template <>
diff --git a/include/mbgl/style/sources/vector_source.hpp b/include/mbgl/style/sources/vector_source.hpp
index e16a6a68a..8626ce160 100644
--- a/include/mbgl/style/sources/vector_source.hpp
+++ b/include/mbgl/style/sources/vector_source.hpp
@@ -11,9 +11,12 @@ class VectorSource : public Source {
 public:
     VectorSource(std::string id, variant<std::string, Tileset> urlOrTileset);
 
+    optional<std::string> getURL() const;
+
     // Private implementation
 
     class Impl;
+    Impl* const impl;
 };
 
 template <>
diff --git a/src/mbgl/style/sources/geojson_source.cpp b/src/mbgl/style/sources/geojson_source.cpp
index 748043813..62726cd12 100644
--- a/src/mbgl/style/sources/geojson_source.cpp
+++ b/src/mbgl/style/sources/geojson_source.cpp
@@ -18,7 +18,7 @@ void GeoJSONSource::setGeoJSON(const mapbox::geojson::geojson& geoJSON) {
     impl->setGeoJSON(geoJSON);
 }
 
-optional<std::string> GeoJSONSource::getURL() {
+optional<std::string> GeoJSONSource::getURL() const {
     return impl->getURL();
 }
 
diff --git a/src/mbgl/style/sources/geojson_source_impl.cpp b/src/mbgl/style/sources/geojson_source_impl.cpp
index 4800b9c4b..2929d73d3 100644
--- a/src/mbgl/style/sources/geojson_source_impl.cpp
+++ b/src/mbgl/style/sources/geojson_source_impl.cpp
@@ -47,7 +47,7 @@ void GeoJSONSource::Impl::setURL(std::string url_) {
     }
 }
 
-optional<std::string> GeoJSONSource::Impl::getURL() {
+optional<std::string> GeoJSONSource::Impl::getURL() const {
     return url;
 }
 
diff --git a/src/mbgl/style/sources/geojson_source_impl.hpp b/src/mbgl/style/sources/geojson_source_impl.hpp
index 13994d907..eec7cf060 100644
--- a/src/mbgl/style/sources/geojson_source_impl.hpp
+++ b/src/mbgl/style/sources/geojson_source_impl.hpp
@@ -17,7 +17,7 @@ public:
     ~Impl() final;
 
     void setURL(std::string);
-    optional<std::string> getURL();
+    optional<std::string> getURL() const;
 
     void setGeoJSON(const GeoJSON&);
     void setTileData(GeoJSONTile&, const OverscaledTileID& tileID);
diff --git a/src/mbgl/style/sources/raster_source.cpp b/src/mbgl/style/sources/raster_source.cpp
index 3c65476df..94fdbcef1 100644
--- a/src/mbgl/style/sources/raster_source.cpp
+++ b/src/mbgl/style/sources/raster_source.cpp
@@ -5,7 +5,17 @@ namespace mbgl {
 namespace style {
 
 RasterSource::RasterSource(std::string id, variant<std::string, Tileset> urlOrTileset, uint16_t tileSize)
-    : Source(SourceType::Raster, std::make_unique<RasterSource::Impl>(std::move(id), *this, std::move(urlOrTileset), tileSize)) {
+    : Source(SourceType::Raster, std::make_unique<RasterSource::Impl>(std::move(id), *this, std::move(urlOrTileset), tileSize)),
+      impl(static_cast<Impl*>(baseImpl.get())) {
+}
+
+optional<std::string> RasterSource::getURL() const {
+    auto urlOrTileset = impl->getURLOrTileset();
+    if (urlOrTileset.is<std::string>()) {
+        return urlOrTileset.get<std::string>();
+    } else {
+        return {};
+    }
 }
 
 } // namespace style
diff --git a/src/mbgl/style/sources/vector_source.cpp b/src/mbgl/style/sources/vector_source.cpp
index f2a6b166a..4bcd3b898 100644
--- a/src/mbgl/style/sources/vector_source.cpp
+++ b/src/mbgl/style/sources/vector_source.cpp
@@ -5,7 +5,17 @@ namespace mbgl {
 namespace style {
 
 VectorSource::VectorSource(std::string id, variant<std::string, Tileset> urlOrTileset)
-    : Source(SourceType::Vector, std::make_unique<VectorSource::Impl>(std::move(id), *this, std::move(urlOrTileset))) {
+    : Source(SourceType::Vector, std::make_unique<VectorSource::Impl>(std::move(id), *this, std::move(urlOrTileset))),
+      impl(static_cast<Impl*>(baseImpl.get())) {
+}
+
+optional<std::string> VectorSource::getURL() const {
+    auto urlOrTileset = impl->getURLOrTileset();
+    if (urlOrTileset.is<std::string>()) {
+        return urlOrTileset.get<std::string>();
+    } else {
+        return {};
+    }
 }
 
 } // namespace style