diff --git imagefield_widget.inc imagefield_widget.inc
index d184a8a..f3d2b38 100644
--- imagefield_widget.inc
+++ imagefield_widget.inc
@@ -171,7 +171,7 @@ function _imagefield_widget_settings_default_validate($element, &$form_state) {
 function imagefield_widget_settings_validate($widget) {
   // Check that only web images are specified in the callback.
   $extensions = array_filter(explode(' ', $widget['file_extensions']));
-  $web_extensions = array('jpg', 'jpeg', 'gif', 'png');
+  $web_extensions = array('jpg', 'jpeg', 'gif', 'png', 'JPG', 'JPEG', 'GIF', 'PNG');
   if (count(array_diff($extensions, $web_extensions))) {
     form_set_error('file_extensions', t('Only web-standard images (jpg, gif, and png) are supported through the image widget. If needing to upload other types of images, change the widget to use a standard file upload.'));
   }