diff --git a/imagemagick.module b/imagemagick.module
index 804338f..15151be 100644
--- a/imagemagick.module
+++ b/imagemagick.module
@@ -477,14 +477,13 @@ function _imagemagick_convert_exec($command_args, &$output = NULL, &$error = NUL
   );
   if ($h = proc_open($command, $descriptors, $pipes, $drupal_path)) {
     $output = '';
-    while (!feof($pipes[1])) {
-      $output .= fgets($pipes[1]);
-    }
     $error = '';
-    while (!feof($pipes[2])) {
+    stream_set_blocking($pipes[1], FALSE);
+    stream_set_blocking($pipes[2], FALSE);
+    while (!feof($pipes[1]) && !feof($pipes[2])) {
+      $output .= fgets($pipes[1]);
       $error .= fgets($pipes[2]);
     }
-
     fclose($pipes[0]);
     fclose($pipes[1]);
     fclose($pipes[2]);