diff --git a/include/common.inc.php b/include/common.inc.php
index e39337950..c3e6cfe12 100644
--- a/include/common.inc.php
+++ b/include/common.inc.php
@@ -166,7 +166,7 @@ elseif ('pt_BR' == $user['language']) {
 else {
   define('PHPWG_DOMAIN', 'piwigo.org');
 }
-define('PHPWG_URL', 'http://'.PHPWG_DOMAIN);
+define('PHPWG_URL', 'https://'.PHPWG_DOMAIN);
 
 if(isset($conf['alternative_pem_url']) and $conf['alternative_pem_url']!='')
 {
@@ -174,7 +174,7 @@ if(isset($conf['alternative_pem_url']) and $conf['alternative_pem_url']!='')
 }
 else
 {
-  define('PEM_URL', 'http://'.PHPWG_DOMAIN.'/ext');
+  define('PEM_URL', 'https://'.PHPWG_DOMAIN.'/ext');
 }
 
 // language files
diff --git a/install.php b/install.php
index 883fb981d..ab825cb7e 100644
--- a/install.php
+++ b/install.php
@@ -229,7 +229,7 @@ else if ('pt_BR' == $language) {
 else {
   define('PHPWG_DOMAIN', 'piwigo.org');
 }
-define('PHPWG_URL', 'http://'.PHPWG_DOMAIN);
+define('PHPWG_URL', 'https://'.PHPWG_DOMAIN);
 
 load_language('common.lang', '', array('language' => $language, 'target_charset'=>'utf-8'));
 load_language('admin.lang', '', array('language' => $language, 'target_charset'=>'utf-8'));
diff --git a/upgrade.php b/upgrade.php
index 97908f627..ecf84cdf5 100644
--- a/upgrade.php
+++ b/upgrade.php
@@ -183,7 +183,7 @@ else if ('pt_BR' == $language) {
 else {
   define('PHPWG_DOMAIN', 'piwigo.org');
 }
-define('PHPWG_URL', 'http://'.PHPWG_DOMAIN);
+define('PHPWG_URL', 'https://'.PHPWG_DOMAIN);
 
 load_language( 'common.lang', '', array('language'=>$language, 'target_charset'=>'utf-8', 'no_fallback' => true) );
 load_language( 'admin.lang', '', array('language'=>$language, 'target_charset'=>'utf-8', 'no_fallback' => true) );