diff --git a/admin/include/languages.class.php b/admin/include/languages.class.php
index 69918009a..5dc846fe0 100644
--- a/admin/include/languages.class.php
+++ b/admin/include/languages.class.php
@@ -30,6 +30,11 @@ class languages
   {
     global $conf;
 
+    if (!$conf['enable_extensions_install'] and 'delete' == $action)
+    {
+      die('Piwigo extensions install/update/delete system is disabled');
+    }
+
     if (isset($this->db_languages[$language_id]))
     {
       $crt_db_language = $this->db_languages[$language_id];
diff --git a/admin/include/plugins.class.php b/admin/include/plugins.class.php
index 92a469495..3fb266526 100644
--- a/admin/include/plugins.class.php
+++ b/admin/include/plugins.class.php
@@ -107,6 +107,13 @@ class plugins
    */
   function perform_action($action, $plugin_id, $options=array())
   {
+    global $conf;
+
+    if (!$conf['enable_extensions_install'] and 'delete' == $action)
+    {
+      die('Piwigo extensions install/update/delete system is disabled');
+    }
+
     if (isset($this->db_plugins_by_id[$plugin_id]))
     {
       $crt_db_plugin = $this->db_plugins_by_id[$plugin_id];
diff --git a/admin/include/themes.class.php b/admin/include/themes.class.php
index 47191a9e4..fa53e7e15 100644
--- a/admin/include/themes.class.php
+++ b/admin/include/themes.class.php
@@ -88,6 +88,11 @@ class themes
   {
     global $conf;
 
+    if (!$conf['enable_extensions_install'] and 'delete' == $action)
+    {
+      die('Piwigo extensions install/update/delete system is disabled');
+    }
+
     if (isset($this->db_themes_by_id[$theme_id]))
     {
       $crt_db_theme = $this->db_themes_by_id[$theme_id];
diff --git a/admin/languages_installed.php b/admin/languages_installed.php
index 8b0cf4e06..97e2a2fb0 100644
--- a/admin/languages_installed.php
+++ b/admin/languages_installed.php
@@ -117,6 +117,7 @@ DELETE
 
 $template->assign('isWebmaster', (is_webmaster()) ? 1 : 0);
 $template->assign('ADMIN_PAGE_TITLE', l10n('Languages'));
+$template->assign('CONF_ENABLE_EXTENSIONS_INSTALL', $conf['enable_extensions_install']);
 
 $template->assign_var_from_handle('ADMIN_CONTENT', 'languages');
 ?>
diff --git a/admin/plugins_installed.php b/admin/plugins_installed.php
index c2587cd2c..ce7e97d6b 100644
--- a/admin/plugins_installed.php
+++ b/admin/plugins_installed.php
@@ -196,6 +196,7 @@ $template->assign(
     'isWebmaster' => (is_webmaster()) ? 1 : 0,
     'ADMIN_PAGE_TITLE' => l10n('Plugins'),
     'view_selector' => userprefs_get_param('plugin-manager-view', 'classic'),
+    'CONF_ENABLE_EXTENSIONS_INSTALL' => $conf['enable_extensions_install'],
     )
   );
 
diff --git a/admin/themes/default/template/languages_installed.tpl b/admin/themes/default/template/languages_installed.tpl
index 6b0b8807c..8670ec427 100644
--- a/admin/themes/default/template/languages_installed.tpl
+++ b/admin/themes/default/template/languages_installed.tpl
@@ -48,7 +48,9 @@ $(".delete-lang-button").each(function() {
 
       {if $language_state == 'inactive'}
       <a href="{$language.u_action}&amp;action=activate" class="tiptip" title="{'Make this language available to users'|@translate}">{'Activate'|@translate}</a>
+        {if $CONF_ENABLE_EXTENSIONS_INSTALL}
       | <a href="{$language.u_action}&amp;action=delete" class="tiptip delete-lang-button" title="{'Delete this language'|@translate}">{'Delete'|@translate}</a>
+        {/if}
       {/if}
       </div>
     </div> <!-- languageActions -->
diff --git a/admin/themes/default/template/plugins_installed.tpl b/admin/themes/default/template/plugins_installed.tpl
index ac4b92fc8..74d52faea 100644
--- a/admin/themes/default/template/plugins_installed.tpl
+++ b/admin/themes/default/template/plugins_installed.tpl
@@ -151,7 +151,7 @@ let plugin_filter = searchParams.get('filter');
           <div class="tiptip" title="{'Uninstall'|@translate}">
             <a class="uninstall-plugin-button">{'Uninstall'|@translate}</a>
           </div>
-        {elseif $plugin.STATE == 'merged'}
+        {elseif $plugin.STATE == 'merged' and $CONF_ENABLE_EXTENSIONS_INSTALL}
           <div class="tiptip" title="{'Delete'|@translate}">
             <a class="" href="{$plugin.U_ACTION}&amp;action=delete">{'Delete'|@translate}</a>
           </div>
@@ -164,7 +164,9 @@ let plugin_filter = searchParams.get('filter');
           {$plugin.DESC}
         </div>
           <a class="dropdown-option icon-back-in-time plugin-restore separator-top tiptip" title="{'While restoring this plugin, it will be reset to its original parameters and associated data is going to be reset'|@translate}">{'Restore'|@translate}</a>
+  {if $CONF_ENABLE_EXTENSIONS_INSTALL}
           <a class="dropdown-option icon-trash delete-plugin-button separator-top">{'Delete'|@translate}</a>
+  {/if}
       </div>
       <div class="pluginName" data-title="{$plugin.NAME}">
         {$plugin.NAME}
@@ -187,7 +189,7 @@ let plugin_filter = searchParams.get('filter');
           {/if}
         {elseif $plugin.STATE == 'missing'}
           <a class="pluginActionLevel3 uninstall-plugin-button">{'Uninstall'|@translate}</a>
-        {elseif $plugin.STATE == 'merged'}
+        {elseif $plugin.STATE == 'merged' and $CONF_ENABLE_EXTENSIONS_INSTALL}
           <a class="pluginActionLevel3" href="{$plugin.U_ACTION}&amp;action=delete">{'Delete'|@translate}</a>
         {/if}                     
       </div>
diff --git a/admin/themes/default/template/themes_installed.tpl b/admin/themes/default/template/themes_installed.tpl
index b06c5662d..7f175c2a0 100644
--- a/admin/themes/default/template/themes_installed.tpl
+++ b/admin/themes/default/template/themes_installed.tpl
@@ -114,7 +114,7 @@ $(window).bind("load", function() {
       <div class="showInfo-dropdown-content">
         {$theme.DESC|@escape:'html'}
       </div>
-      {if $theme.STATE != "active"}
+      {if $theme.STATE != "active" and $CONF_ENABLE_EXTENSIONS_INSTALL}
         {if $theme.DELETABLE}
             <a class="dropdown-option icon-trash delete-plugin-button delete-theme-button" href="{$delete_baseurl}{$theme.ID}">{'Delete'|@translate}</a>
         {else}
diff --git a/admin/themes_installed.php b/admin/themes_installed.php
index ecb28dcab..2815a5875 100644
--- a/admin/themes_installed.php
+++ b/admin/themes_installed.php
@@ -170,6 +170,7 @@ trigger_notify('loc_end_themes_installed');
 
 $template->assign('isWebmaster', (is_webmaster()) ? 1 : 0);
 $template->assign('ADMIN_PAGE_TITLE', l10n('Themes'));
+$template->assign('CONF_ENABLE_EXTENSIONS_INSTALL', $conf['enable_extensions_install']);
 
 $template->set_filenames(array('themes' => 'themes_installed.tpl'));
 $template->assign_var_from_handle('ADMIN_CONTENT', 'themes');
diff --git a/include/ws_functions/pwg.extensions.php b/include/ws_functions/pwg.extensions.php
index 997f79763..c8e806d67 100644
--- a/include/ws_functions/pwg.extensions.php
+++ b/include/ws_functions/pwg.extensions.php
@@ -52,7 +52,7 @@ function ws_plugins_getList($params, $service)
  */
 function ws_plugins_performAction($params, $service)
 {
-  global $template;
+  global $template, $conf;
 
   if (get_pwg_token() != $params['pwg_token'])
   {
@@ -64,6 +64,11 @@ function ws_plugins_performAction($params, $service)
     return new PwgError(403, l10n('Webmaster status is required.'));
   }
 
+  if (!$conf['enable_extensions_install'] and 'delete' == $params['action'])
+  {
+    return new PwgError(401, 'Piwigo extensions install/update/delete system is disabled');
+  }
+
   define('IN_ADMIN', true);
   include_once(PHPWG_ROOT_PATH.'admin/include/plugins.class.php');
 
@@ -94,13 +99,18 @@ function ws_plugins_performAction($params, $service)
  */
 function ws_themes_performAction($params, $service)
 {
-  global $template;
+  global $template, $conf;
 
   if (get_pwg_token() != $params['pwg_token'])
   {
     return new PwgError(403, 'Invalid security token');
   }
 
+  if (!$conf['enable_extensions_install'] and 'delete' == $params['action'])
+  {
+    return new PwgError(401, 'Piwigo extensions install/update/delete system is disabled');
+  }
+
   define('IN_ADMIN', true);
   include_once(PHPWG_ROOT_PATH.'admin/include/themes.class.php');