diff --git ie_css_optimizer.module ie_css_optimizer.module
index 7676150..60ed27a 100644
--- ie_css_optimizer.module
+++ ie_css_optimizer.module
@@ -2,7 +2,7 @@
 /**
  * Implements HOOK_preprocess_page().
  */
-function ie_css_optimizer_preprocess_page(&$vars, $hook) {
+function ie_css_optimizer_final_preprocess_page(&$vars, $hook) {
   $preprocess_css = variable_get('preprocess_css', 0);
   if ($preprocess_css == 'theme' || $preprocess_css == 'module') {
     module_load_include('inc', 'ie_css_optimizer', 'ie_css_optimizer.pages');
@@ -17,3 +17,11 @@ function ie_css_optimizer_form_system_performance_settings_alter(&$form, $form_s
   module_load_include('inc', 'ie_css_optimizer', 'ie_css_optimizer.admin');
   _ie_css_optimizer_form_system_performance_settings_alter($form, $form_state);
 }
+
+/**
+ * Implements HOOK_theme_registry_alter().
+ */
+function ie_css_optimizer_theme_registry_alter(&$theme_registry) {
+  // Set the preprocess function to run last to avoid complications with ctools.
+  $theme_registry['page']['preprocess functions'][] = 'ie_css_optimizer_final_preprocess_page';
+}