diff --git a/auth/ldap/auth.php b/auth/ldap/auth.php
index 6dbf68d..52c96f0 100644
--- a/auth/ldap/auth.php
+++ b/auth/ldap/auth.php
@@ -1543,8 +1543,8 @@ class auth_plugin_ldap extends auth_plugin_base {
             $connresult = ldap_connect($server);
             //ldap_connect returns ALWAYS true
 
-            if (!empty($this->config->version)) {
-                ldap_set_option($connresult, LDAP_OPT_PROTOCOL_VERSION, $this->config->version);
+            if (!empty($this->config->ldapversion)) {
+                ldap_set_option($connresult, LDAP_OPT_PROTOCOL_VERSION, $this->config->ldapversion);
             }
 
             // Fix MDL-10921
@@ -1995,8 +1995,8 @@ class auth_plugin_ldap extends auth_plugin_base {
             {$config->bind_dn = ''; }
         if (!isset($config->bind_pw))
             {$config->bind_pw = ''; }
-        if (!isset($config->version))
-            {$config->version = '2'; }
+        if (!isset($config->ldapversion))
+            {$config->ldapversion = '2'; }
         if (!isset($config->objectclass))
             {$config->objectclass = ''; }
         if (!isset($config->memberattribute))
@@ -2048,7 +2048,7 @@ class auth_plugin_ldap extends auth_plugin_base {
         set_config('preventpassindb', $config->preventpassindb, 'auth/ldap');
         set_config('bind_dn', $config->bind_dn, 'auth/ldap');
         set_config('bind_pw', $config->bind_pw, 'auth/ldap');
-        set_config('version', $config->version, 'auth/ldap');
+        set_config('ldapversion', $config->ldapversion, 'auth/ldap');
         set_config('objectclass', trim($config->objectclass), 'auth/ldap');
         set_config('memberattribute', $config->memberattribute, 'auth/ldap');
         set_config('memberattribute_isdn', $config->memberattribute_isdn, 'auth/ldap');
diff --git a/auth/ldap/config.html b/auth/ldap/config.html
index cb9ee66..ef56e5b 100644
--- a/auth/ldap/config.html
+++ b/auth/ldap/config.html
@@ -21,8 +21,8 @@
         {$config->bind_dn = ''; }
     if (!isset($config->bind_pw))
         {$config->bind_pw = ''; }
-    if (!isset($config->version))
-        {$config->version = '2'; }
+    if (!isset($config->ldapversion))
+        {$config->ldapversion = '2'; }
     if (!isset($config->objectclass))
         {$config->objectclass = ''; }
     if (!isset($config->memberattribute))
@@ -95,8 +95,8 @@ if (!function_exists('ldap_connect')) { // Is php4-ldap really there?
        $versions = array();
        $versions[2] = '2';
        $versions[3] = '3';
-       echo html_writer::select($versions, 'version', $config->version, false);
-       if (isset($err['version'])) echo $OUTPUT->error_text($err['version']);
+       echo html_writer::select($versions, 'ldapversion', $config->ldapversion, false);
+       if (isset($err['ldapversion'])) echo $OUTPUT->error_text($err['ldapversion']);
     ?>
     </td>
     <td>
diff --git a/auth/ldap/db/install.php b/auth/ldap/db/install.php
index f508bf8..16fa485 100644
--- a/auth/ldap/db/install.php
+++ b/auth/ldap/db/install.php
@@ -10,4 +10,17 @@ function xmldb_auth_ldap_install() {
         $DB->set_field('user', 'password', 'not cached', array('auth'=>'ldap'));
     }
 
+    // We kept the LDAP version used to connect to the server in
+    // $config->version. In 2.0, $config->version is overwritten with
+    // the plugin version number, so we need to change the setting
+    // name. Let's call it 'ldapversion' and remove the old setting.
+    //
+    // This works by pure luck, as the plugin version number is stored in
+    // config_plugins table before we get called. The good news is the new
+    // version number is stored for 'auth_ldap' plugin name, while the old ldap
+    // version setting is stored for 'auth/ldap' plugin name. Yay!
+    if ($ldapversion = get_config('auth/ldap', 'version')) {
+        set_config('ldapversion', $ldapversion, 'auth/ldap');
+        unset_config('version', 'auth/ldap');
+    }
 }