diff --git a/plugins/Authentication/AuthenticationPlugin.php b/plugins/Authentication/AuthenticationPlugin.php
index 1b9084187b..cd1de11491 100644
--- a/plugins/Authentication/AuthenticationPlugin.php
+++ b/plugins/Authentication/AuthenticationPlugin.php
@@ -2,7 +2,7 @@
 /**
  * StatusNet, the distributed open-source microblogging tool
  *
- * Superclass for plugins that do authentication and/or authorization
+ * Superclass for plugins that do authentication
  *
  * PHP version 5
  *
diff --git a/plugins/LdapAuthentication/LdapAuthenticationPlugin.php b/plugins/LdapAuthentication/LdapAuthenticationPlugin.php
index ad5dd3a022..664529497c 100644
--- a/plugins/LdapAuthentication/LdapAuthenticationPlugin.php
+++ b/plugins/LdapAuthentication/LdapAuthenticationPlugin.php
@@ -63,6 +63,8 @@ class LdapAuthenticationPlugin extends AuthenticationPlugin
         if(!isset($this->attributes['username'])){
             throw new Exception("must specify a username attribute");
         }
+        if($this->password_changeable && (! isset($this->attributes['password']) || !isset($this->password_encoding))){
+            throw new Exception("if password_changeable is set, the password attribute and password_encoding must also be specified");
     }
     
     //---interface implementation---//