diff --git a/modules/system/system.admin.inc b/modules/system/system.admin.inc
index 88f8d410a12a5b26cd8ded5f2b338d7dcc225da2..54f7cca16b627f200f71c43cc930257652fbce51 100644
--- a/modules/system/system.admin.inc
+++ b/modules/system/system.admin.inc
@@ -559,11 +559,7 @@ function system_theme_settings(&$form_state, $key = '') {
 function system_theme_settings_submit($form, &$form_state) {
   $values = $form_state['values'];
   if (empty($values['default_favicon']) && !empty($values['favicon_path'])) {
-    $mimetype = file_get_mimetype($values['favicon_path']);
-    // Use the default MIME type for favicons if no other was found.
-    if ($mimetype != 'application/octet-stream') {
-      $values['favicon_mimetype'] = $mimetype;
-    }
+    $values['favicon_mimetype'] = file_get_mimetype($values['favicon_path']);
   }
   $key = $values['var'];