diff --git a/src/gui/image/qpnghandler.cpp b/src/gui/image/qpnghandler.cpp
index e43ac666c7..7838b7df8e 100644
--- a/src/gui/image/qpnghandler.cpp
+++ b/src/gui/image/qpnghandler.cpp
@@ -591,14 +591,14 @@ bool Q_INTERNAL_WIN_NO_THROW QPngHandlerPrivate::readPngImage(QImage *outImage)
     if (doScaledRead) {
         read_image_scaled(outImage, png_ptr, info_ptr, amp, scaledSize);
     } else {
-        png_uint_32 width;
-        png_uint_32 height;
-        png_int_32 offset_x;
-        png_int_32 offset_y;
+        png_uint_32 width = 0;
+        png_uint_32 height = 0;
+        png_int_32 offset_x = 0;
+        png_int_32 offset_y = 0;
 
-        int bit_depth;
-        int color_type;
-        int unit_type;
+        int bit_depth = 0;
+        int color_type = 0;
+        int unit_type = PNG_OFFSET_PIXEL;
         png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth, &color_type, 0, 0, 0);
         png_get_oFFs(png_ptr, info_ptr, &offset_x, &offset_y, &unit_type);
         uchar *data = outImage->bits();