diff --git a/include/mbgl/platform/default/png_reader.hpp b/include/mbgl/platform/default/png_reader.hpp
index f6b5aaf9c..db20d85e2 100644
--- a/include/mbgl/platform/default/png_reader.hpp
+++ b/include/mbgl/platform/default/png_reader.hpp
@@ -49,7 +49,7 @@ public:
     unsigned width() const;
     unsigned height() const;
     inline bool has_alpha() const { return has_alpha_; }
-    bool premultiplied_alpha() const { return false; } //http://www.libpng.org/pub/png/spec/1.1/PNG-Rationale.html
+    bool premultiplied_alpha() const { return true; } // png_set_alpha_mode(png, PNG_ALPHA_PREMULTIPLIED, 2.2)
     void read(unsigned x,unsigned y, unsigned width, unsigned height, char * image);
 private:
     void init();
diff --git a/platform/default/png_reader.cpp b/platform/default/png_reader.cpp
index e9f38a9d3..507db715a 100644
--- a/platform/default/png_reader.cpp
+++ b/platform/default/png_reader.cpp
@@ -157,6 +157,7 @@ void png_reader<T>::read(unsigned x0, unsigned y0, unsigned w, unsigned h, char
     double gamma;
     if (png_get_gAMA(png_ptr, info_ptr, &gamma))
         png_set_gamma(png_ptr, 2.2, gamma);
+    png_set_alpha_mode(png_ptr, PNG_ALPHA_PREMULTIPLIED, 2.2);
 
     if (x0 == 0 && y0 == 0 && w >= width_ && h >= height_)
     {