diff --git a/sites/all/libraries/dompdf/lib/class.pdf.php b/sites/all/libraries/dompdf/lib/class.pdf.php
index 948b303..f60967c 100644
--- a/sites/all/libraries/dompdf/lib/class.pdf.php
+++ b/sites/all/libraries/dompdf/lib/class.pdf.php
@@ -4326,7 +4326,9 @@ EOT;
       $imagick->setFormat('png');
       
       // Get opacity channel (negative of alpha channel)
-      $alpha_channel = clone $imagick;
+      //$alpha_channel = clone $imagick;
+      $alpha_channel = new Imagick($file);
+      $alpha_channel->setFormat('png');
       $alpha_channel->separateImageChannel(Imagick::CHANNEL_ALPHA);
       $alpha_channel->negateImage(true);
       $alpha_channel->writeImage($tempfile_alpha);