diff --git a/modules/juce_graphics/image_formats/juce_PNGLoader.cpp b/modules/juce_graphics/image_formats/juce_PNGLoader.cpp
index eecf7e56d8..172868661f 100644
--- a/modules/juce_graphics/image_formats/juce_PNGLoader.cpp
+++ b/modules/juce_graphics/image_formats/juce_PNGLoader.cpp
@@ -332,14 +332,6 @@ namespace PNGHelpers
         static_cast<OutputStream*> (png_get_io_ptr (png))->write (data, length);
     }
 
-   #if ! JUCE_USING_COREIMAGE_LOADER
-    static void JUCE_CDECL readCallback (png_structp png, png_bytep data, png_size_t length)
-    {
-        static_cast<InputStream*> (png_get_io_ptr (png))->read (data, (int) length);
-    }
-
-    struct PNGErrorStruct {};
-
     static void JUCE_CDECL errorCallback (png_structp p, png_const_charp)
     {
        #ifdef PNG_SETJMP_SUPPORTED
@@ -351,6 +343,14 @@ namespace PNGHelpers
 
     static void JUCE_CDECL warningCallback (png_structp, png_const_charp) {}
 
+    #if ! JUCE_USING_COREIMAGE_LOADER
+    static void JUCE_CDECL readCallback (png_structp png, png_bytep data, png_size_t length)
+    {
+        static_cast<InputStream*> (png_get_io_ptr (png))->read (data, (int) length);
+    }
+
+    struct PNGErrorStruct {};
+
     JUCE_BEGIN_IGNORE_WARNINGS_MSVC (4611)
 
     static bool readHeader (InputStream& in, png_structp pngReadStruct, png_infop pngInfoStruct, jmp_buf& errorJumpBuf,
@@ -528,15 +528,31 @@ Image PNGImageFormat::decodeImage (InputStream& in)
 
 bool PNGImageFormat::writeImageToStream (const Image& image, OutputStream& out)
 {
+    if (! image.isValid())
+        return false;
+
     using namespace pnglibNamespace;
     auto width = image.getWidth();
     auto height = image.getHeight();
 
+    HeapBlock<uint8> rowData (width * 4);
+    const Image::BitmapData srcData (image, Image::BitmapData::readOnly);
+
     auto pngWriteStruct = png_create_write_struct (PNG_LIBPNG_VER_STRING, nullptr, nullptr, nullptr);
 
     if (pngWriteStruct == nullptr)
         return false;
 
+    jmp_buf errorJumpBuf;
+    png_set_error_fn (pngWriteStruct, &errorJumpBuf, PNGHelpers::errorCallback, PNGHelpers::warningCallback);
+
+    JUCE_BEGIN_IGNORE_WARNINGS_MSVC (4611)
+
+    if (setjmp (errorJumpBuf) != 0)
+        return false;
+
+    JUCE_END_IGNORE_WARNINGS_MSVC
+
     auto pngInfoStruct = png_create_info_struct (pngWriteStruct);
 
     if (pngInfoStruct == nullptr)
@@ -554,8 +570,6 @@ bool PNGImageFormat::writeImageToStream (const Image& image, OutputStream& out)
                   PNG_COMPRESSION_TYPE_BASE,
                   PNG_FILTER_TYPE_BASE);
 
-    HeapBlock<uint8> rowData (width * 4);
-
     png_color_8 sig_bit;
     sig_bit.red   = 8;
     sig_bit.green = 8;
@@ -569,8 +583,6 @@ bool PNGImageFormat::writeImageToStream (const Image& image, OutputStream& out)
     png_set_shift (pngWriteStruct, &sig_bit);
     png_set_packing (pngWriteStruct);
 
-    const Image::BitmapData srcData (image, Image::BitmapData::readOnly);
-
     for (int y = 0; y < height; ++y)
     {
         uint8* dst = rowData;