diff --git a/theme/views_slideshow.theme.inc b/theme/views_slideshow.theme.inc
index 33294e0..aced7b2 100644
--- a/theme/views_slideshow.theme.inc
+++ b/theme/views_slideshow.theme.inc
@@ -70,10 +70,10 @@ function _views_slideshow_preprocess_views_slideshow(&$vars) {
     foreach ($addons as $addon_id => $addon_info) {
       foreach ($addon_info['accepts'] as $imp_key => $imp_value) {
         if (is_array($imp_value)) {
-          $methods[$imp_key][] = preg_replace('/_(.?)/e',"strtoupper('$1')", $addon_id);
+          $methods[$imp_key][] = views_slideshow_format_addons_name($addon_id);
         }
         else {
-          $methods[$imp_value][] = preg_replace('/_(.?)/e',"strtoupper('$1')", $addon_id);
+          $methods[$imp_value][] = views_slideshow_format_addons_name($addon_id);
         }
       }
     }
@@ -189,7 +189,7 @@ function theme_views_slideshow_pager_widget_render($vss_id, $view, $settings, $l
     'viewsSlideshowPager' => array(
       $vss_id => array(
         $location => array(
-          'type' => preg_replace('/_(.?)/e',"strtoupper('$1')", $settings['type']),
+          'type' => views_slideshow_format_addons_name($settings['type'])
         ),
       ),
     ),
@@ -284,7 +284,7 @@ function theme_views_slideshow_controls_widget_render($vss_id, $view, $settings,
     'viewsSlideshowControls' => array(
       $vss_id => array(
         $location => array(
-          'type' => preg_replace('/_(.?)/e',"strtoupper('$1')", $settings['type']),
+          'type' => views_slideshow_format_addons_name($settings['type'])
         ),
       ),
     ),
diff --git a/views_slideshow.module b/views_slideshow.module
index 5628f0d..78cf57d 100644
--- a/views_slideshow.module
+++ b/views_slideshow.module
@@ -460,3 +460,20 @@ function template_preprocess_views_slideshow_controls_text_next(&$vars) {
 function template_preprocess_views_slideshow_slide_counter(&$vars) {
   _views_slideshow_preprocess_views_slideshow_slide_counter($vars);
 }
+
+/**
+ * preg_replace_callback callback().
+ * @see views_slideshow_format_addons_name().
+ */
+function _views_slideshow_get_preg_strtoupper_callback($matches) {
+  if (isset($matches[1])) {
+    return strtoupper($matches[1]);
+  }
+}
+
+/**
+ * php5.x preg_replace_callback() method.
+ */
+function views_slideshow_format_addons_name($subject) {
+  return preg_replace_callback('/_(.?)/', '_views_slideshow_get_preg_strtoupper_callback', $subject);
+}
\ No newline at end of file
diff --git a/views_slideshow_plugin_style_slideshow.inc b/views_slideshow_plugin_style_slideshow.inc
index 150b578..d40a5c5 100644
--- a/views_slideshow_plugin_style_slideshow.inc
+++ b/views_slideshow_plugin_style_slideshow.inc
@@ -221,7 +221,7 @@ class views_slideshow_plugin_style_slideshow extends views_plugin_style {
   }
 
   // Run any validation on the form settings.
-  function options_validate(&$form, &$form_state) {
+  function options_validate($form, &$form_state) {
     module_load_all_includes('views_slideshow.inc');
 
     $arguments = array(