diff --git a/core/includes/update.inc b/core/includes/update.inc
index 9c9a65c..5556690 100644
--- a/core/includes/update.inc
+++ b/core/includes/update.inc
@@ -229,7 +229,7 @@ function update_do_one($module, $number, $dependency_map, &$context) {
 function update_invoke_post_update($function, &$context) {
   $ret = [];
 
-  list($module, ) = explode('_post_update_', $function);
+  list($module, ) = explode('_post_update_', $function, 2);
   module_load_include('php', $module, $module . '.post_update');
   if (function_exists($function)) {
     try {