--- password_change/password_change.install.orig	Wed Oct 27 06:29:43 2010
+++ password_change/password_change.install	Wed Oct 27 06:33:46 2010
@@ -6,6 +6,15 @@
  * Install and uninstall schema and functions for the password_change module.
  */
 
+// based on phpass.module
+function password_change_install() {
+  // detect presence of phpass module (phpass hash method set as 'phpass')
+  if (module_exists("phpass") && variable_get('user_hash_method', 'phpass') == 'phpass') {
+    // check if PasswordHash.php is missing (phpass.module)
+    _phpass_is_passwordhash_php_missing();
+  }
+}
+
 function password_change_uninstall() {
   variable_del('password_change_all');
 }