diff --git a/htdocs/install/inc.php b/htdocs/install/inc.php
index d53cbc0ff3e..c9d7378101b 100644
--- a/htdocs/install/inc.php
+++ b/htdocs/install/inc.php
@@ -69,7 +69,10 @@ define('DOL_DOCUMENT_ROOT','../');
 // Forcage du log pour les install et mises a jour
 $conf->syslog->enabled=1;
 $conf->global->SYSLOG_LEVEL=constant('LOG_DEBUG');
-if (file_exists('/tmp')) define('SYSLOG_FILE','/tmp/dolibarr_install.log');
+if (is_writable('/tmp')) define('SYSLOG_FILE','/tmp/dolibarr_install.log');
+else if ((isset($_ENV["TMP"] && is_writable($_ENV["TMP"]) || (isset($_ENV["TEMP"] && is_writable($_ENV["TEMP"])) {
+	define('SYSLOG_FILE',($_ENV["TMP"]?$_ENV["TMP"]:$_ENV["TEMP"]).'/dolibarr_install.log');
+}
 else define('SYSLOG_FILE','/dolibarr_install.log');
 define('SYSLOG_FILE_NO_ERROR',1);