diff --git a/includes/mimetype.utils.inc b/includes/mimetype.utils.inc
index 03708f99..81866fc8 100644
--- a/includes/mimetype.utils.inc
+++ b/includes/mimetype.utils.inc
@@ -22,6 +22,8 @@ function islandora_get_extension_for_mimetype($mimetype) {
   $mimetype_mapping = file_mimetype_mapping();
   $extension_index = array_search($mimetype, $mimetype_mapping['mimetypes']);
   if ($extension_index !== FALSE) {
+    // Reversing such that any altered values take precedence over the default
+    // mappings.
     $mime_array_flipped = array_reverse($mimetype_mapping['extensions']);
     $extension = array_search($extension_index, $mime_array_flipped);
   }
diff --git a/islandora.module b/islandora.module
index 2dec1fd9..10d6060f 100644
--- a/islandora.module
+++ b/islandora.module
@@ -1662,6 +1662,12 @@ function islandora_file_mimetype_mapping_alter(&$mapping) {
     end($mapping['mimetypes']);
     $mapping['extensions'][$ext] = key($mapping['mimetypes']);
   }
+  // Get the current XML mapping and unset it so it comes last when we do our
+  // reverse when getting mimetypes from extensions for use in downloads.
+  // @see islandora_get_extension_for_mimetype.
+  $xml_int = $mapping['extensions']['xml'];
+  unset($mapping['extensions']['xml']);
+  $mapping['extensions']['xml'] = $xml_int;
 }
 
 /**