diff --git a/source/base/StarPackedAssetSource.cpp b/source/base/StarPackedAssetSource.cpp
index b335c2f..59e64cc 100644
--- a/source/base/StarPackedAssetSource.cpp
+++ b/source/base/StarPackedAssetSource.cpp
@@ -95,8 +95,8 @@ StringList PackedAssetSource::assetPaths() const {
 
 IODevicePtr PackedAssetSource::open(String const& path) {
   struct AssetReader : public IODevice {
-    AssetReader(FilePtr file, StreamOffset offset, StreamOffset size)
-      : file(file), fileOffset(offset), assetSize(size), assetPos(0) {
+    AssetReader(FilePtr file, String path, StreamOffset offset, StreamOffset size)
+      : file(file), path(path), fileOffset(offset), assetSize(size), assetPos(0) {
       setMode(IOMode::Read);
     }
 
@@ -119,6 +119,10 @@ IODevicePtr PackedAssetSource::open(String const& path) {
       return assetPos;
     }
 
+    String deviceName() const override {
+      return strf("{}:{}", file->deviceName(), path);
+    }
+
     bool atEnd() override {
       return assetPos >= assetSize;
     }
@@ -133,6 +137,7 @@ IODevicePtr PackedAssetSource::open(String const& path) {
     }
 
     FilePtr file;
+    String path;
     StreamOffset fileOffset;
     StreamOffset assetSize;
     StreamOffset assetPos;
@@ -142,7 +147,7 @@ IODevicePtr PackedAssetSource::open(String const& path) {
   if (!p)
     throw AssetSourceException::format("Requested file '{}' does not exist in the packed assets file", path);
 
-  return make_shared<AssetReader>(m_packedFile, p->first, p->second);
+  return make_shared<AssetReader>(m_packedFile, path, p->first, p->second);
 }
 
 ByteArray PackedAssetSource::read(String const& path) {
diff --git a/source/core/StarImage.cpp b/source/core/StarImage.cpp
index 1494503..33c37a4 100644
--- a/source/core/StarImage.cpp
+++ b/source/core/StarImage.cpp
@@ -5,16 +5,19 @@
 
 namespace Star {
 
+void logPngError(png_structp png_ptr, png_const_charp c) {
+  Logger::debug("PNG error in file: '{}', {}", ((IODevice*)png_get_error_ptr(png_ptr))->deviceName(), c);
+};
+
+void logPngWarning(png_structp png_ptr, png_const_charp c) {
+  Logger::debug("PNG warning in file: '{}', {}", ((IODevice*)png_get_error_ptr(png_ptr))->deviceName(), c);
+};
+
+void readPngData(png_structp pngPtr, png_bytep data, png_size_t length) {
+  ((IODevice*)png_get_io_ptr(pngPtr))->readFull((char*)data, length);
+};
+
 Image Image::readPng(IODevicePtr device) {
-  auto logPngError = [](png_structp png_ptr, png_const_charp c) {
-    Logger::debug("PNG error in file: '{}', {}", (char*)png_get_error_ptr(png_ptr), c);
-  };
-
-  auto readPngData = [](png_structp pngPtr, png_bytep data, png_size_t length) {
-    IODevice* device = (IODevice*)png_get_io_ptr(pngPtr);
-    device->readFull((char*)data, length);
-  };
-
   png_byte header[8];
   device->readFull((char*)header, sizeof(header));
 
@@ -26,7 +29,7 @@ Image Image::readPng(IODevicePtr device) {
     throw ImageException("Internal libPNG error");
 
   // Use custom warning function to suppress cerr warnings
-  png_set_error_fn(png_ptr, (png_voidp)device->deviceName().utf8Ptr(), logPngError, logPngError);
+  png_set_error_fn(png_ptr, (png_voidp)device.get(), logPngError, logPngWarning);
 
   png_infop info_ptr = png_create_info_struct(png_ptr);
   if (!info_ptr) {
@@ -111,15 +114,6 @@ Image Image::readPng(IODevicePtr device) {
 }
 
 tuple<Vec2U, PixelFormat> Image::readPngMetadata(IODevicePtr device) {
-  auto logPngError = [](png_structp png_ptr, png_const_charp c) {
-    Logger::debug("PNG error in file: '{}', {}", (char*)png_get_error_ptr(png_ptr), c);
-  };
-
-  auto readPngData = [](png_structp pngPtr, png_bytep data, png_size_t length) {
-    IODevice* device = (IODevice*)png_get_io_ptr(pngPtr);
-    device->readFull((char*)data, length);
-  };
-
   png_byte header[8];
   device->readFull((char*)header, sizeof(header));
 
@@ -131,7 +125,7 @@ tuple<Vec2U, PixelFormat> Image::readPngMetadata(IODevicePtr device) {
     throw ImageException("Internal libPNG error");
 
   // Use custom warning function to suppress cerr warnings
-  png_set_error_fn(png_ptr, (png_voidp)device->deviceName().utf8Ptr(), logPngError, logPngError);
+  png_set_error_fn(png_ptr, (png_voidp)device.get(), logPngError, logPngWarning);
 
   png_infop info_ptr = png_create_info_struct(png_ptr);
   if (!info_ptr) {