diff --git a/libs/gfx/include/psemek/gfx/pixmap.hpp b/libs/gfx/include/psemek/gfx/pixmap.hpp
index 02babf58..788cb429 100644
--- a/libs/gfx/include/psemek/gfx/pixmap.hpp
+++ b/libs/gfx/include/psemek/gfx/pixmap.hpp
@@ -2,6 +2,7 @@
 
 #include <psemek/util/array.hpp>
 #include <psemek/gfx/color.hpp>
+#include <psemek/io/stream.hpp>
 
 #include <memory>
 
@@ -23,7 +24,7 @@ namespace psemek::gfx
 	void write_pgm(pixmap_monochrome const & p, std::ostream & os);
 	void write_ppm(pixmap_rgb const & p, std::ostream & os);
 
-	pixmap_rgba read_png(std::istream & is);
-	pixmap_monochrome read_png_monochrome(std::istream & is);
+	pixmap_rgba read_png(io::istream && is);
+	pixmap_monochrome read_png_monochrome(io::istream && is);
 
 }
diff --git a/libs/gfx/source/painter.cpp b/libs/gfx/source/painter.cpp
index 1209e203..08cc33a7 100644
--- a/libs/gfx/source/painter.cpp
+++ b/libs/gfx/source/painter.cpp
@@ -4,7 +4,7 @@
 #include <psemek/gfx/texture.hpp>
 #include <psemek/gfx/resource/font_9x12_png.hpp>
 #include <psemek/geom/constants.hpp>
-#include <psemek/util/memory_stream.hpp>
+#include <psemek/io/memory_stream.hpp>
 #include <psemek/log/log.hpp>
 
 static const char vertex_source[] =
@@ -164,8 +164,7 @@ namespace psemek::gfx
 			text_mesh.setup<geom::point<float, 3>, gfx::normalized<color_rgba>, geom::point<std::uint16_t, 2>>();
 			texture_mesh.setup<geom::point<float, 3>, gfx::normalized<geom::point<std::uint16_t, 2>>>();
 
-			util::memory_istream font_data(resource::font_9x12_png);
-			font_texture.load(gfx::read_png_monochrome(font_data));
+			font_texture.load(gfx::read_png_monochrome(io::memory_istream{resource::font_9x12_png}));
 
 			font_texture.bind();
 			gl::TexParameteri(gl::TEXTURE_2D, gl::TEXTURE_SWIZZLE_G, gl::RED);
diff --git a/libs/gfx/source/png.cpp b/libs/gfx/source/png.cpp
index 6bd63cb2..76bd5dcd 100644
--- a/libs/gfx/source/png.cpp
+++ b/libs/gfx/source/png.cpp
@@ -9,7 +9,7 @@ namespace psemek::gfx
 {
 
 	template <typename Pixel>
-	basic_pixmap<Pixel> read_png_impl(std::istream & is, png_byte expected_color_type)
+	basic_pixmap<Pixel> read_png_impl(io::istream & is, png_byte expected_color_type)
 	{
 		png_error_ptr error = [](png_structp, png_const_charp str)
 		{
@@ -40,7 +40,7 @@ namespace psemek::gfx
 		if (!end_info) throw std::runtime_error("png_create_info_struct returned null");
 
 		png_rw_ptr read = [](png_structp png, png_bytep ptr, size_t count){
-			reinterpret_cast<std::istream *>(png_get_io_ptr(png))->read(reinterpret_cast<char *>(ptr), count);
+			reinterpret_cast<io::istream *>(png_get_io_ptr(png))->read(reinterpret_cast<char *>(ptr), count);
 		};
 		png_set_read_fn(png, &is, read);
 
@@ -74,12 +74,12 @@ namespace psemek::gfx
 		return result;
 	}
 
-	pixmap_rgba read_png(std::istream & is)
+	pixmap_rgba read_png(io::istream && is)
 	{
 		return read_png_impl<color_rgba>(is, PNG_COLOR_TYPE_RGBA);
 	}
 
-	pixmap_monochrome read_png_monochrome(std::istream & is)
+	pixmap_monochrome read_png_monochrome(io::istream && is)
 	{
 		return read_png_impl<std::uint8_t>(is, PNG_COLOR_TYPE_GRAY);
 	}
diff --git a/libs/ui/source/default_element_factory.cpp b/libs/ui/source/default_element_factory.cpp
index 0ac7a7b3..c0785721 100644
--- a/libs/ui/source/default_element_factory.cpp
+++ b/libs/ui/source/default_element_factory.cpp
@@ -1,7 +1,8 @@
 #include <psemek/ui/default_element_factory.hpp>
 
 #include <psemek/ui/box_shape.hpp>
-#include <psemek/util/memory_stream.hpp>
+
+#include <psemek/io/memory_stream.hpp>
 
 #include <psemek/ui/resources/cross_red_16x16_png.hpp>
 
@@ -548,8 +549,7 @@ namespace psemek::ui
 
 	default_element_factory::impl::impl()
 	{
-		util::memory_istream is{resources::cross_red_16x16_png};
-		cross_red_16x16 = std::make_shared<gfx::texture_2d>(gfx::texture_2d::from_pixmap(gfx::read_png(is)));
+		cross_red_16x16 = std::make_shared<gfx::texture_2d>(gfx::texture_2d::from_pixmap(gfx::read_png(io::memory_istream{resources::cross_red_16x16_png})));
 		cross_red_16x16->nearest_filter();
 	}
 
diff --git a/libs/ui/source/default_fonts.cpp b/libs/ui/source/default_fonts.cpp
index 2a7036b3..77c67099 100644
--- a/libs/ui/source/default_fonts.cpp
+++ b/libs/ui/source/default_fonts.cpp
@@ -3,7 +3,7 @@
 
 #include <psemek/gfx/resource/font_9x12_png.hpp>
 
-#include <psemek/util/memory_stream.hpp>
+#include <psemek/io/memory_stream.hpp>
 
 namespace psemek::ui
 {
@@ -14,8 +14,7 @@ namespace psemek::ui
 		std::string_view name = "default_9x12";
 		geom::vector<int, 2> size{9, 12};
 
-		util::memory_istream is{gfx::resource::font_9x12_png};
-		gfx::texture_2d atlas = gfx::texture_2d::from_pixmap(gfx::read_png_monochrome(is));
+		gfx::texture_2d atlas = gfx::texture_2d::from_pixmap(gfx::read_png_monochrome(io::memory_istream{gfx::resource::font_9x12_png}));
 		atlas.nearest_filter();
 		atlas.clamp();
 		gl::TexParameteri(atlas.target, gl::TEXTURE_SWIZZLE_G, gl::RED);