diff --git page_title/page_title.module page_title/page_title.module
index 321a57c..5af39e2 100644
--- page_title/page_title.module
+++ page_title/page_title.module
@@ -655,7 +655,7 @@ function page_title_include_api_files() {
   // We also avoice using include_once due to its performance hit on the Filesystem
   foreach (page_title_get_module_apis() as $module => $info) {
     if (file_exists(DRUPAL_ROOT . "/{$info['path']}/{$module}.page_title.inc")) {
-      include DRUPAL_ROOT . "/{$info['path']}/{$module}.page_title.inc";
+      include_once DRUPAL_ROOT . "/{$info['path']}/{$module}.page_title.inc";
     }
   }