diff --git a/program/lib/Roundcube/rcube.php b/program/lib/Roundcube/rcube.php
index 39ae90371..9b5a23174 100644
--- a/program/lib/Roundcube/rcube.php
+++ b/program/lib/Roundcube/rcube.php
@@ -1303,7 +1303,6 @@ class rcube
         // log_driver == 'file' is assumed here
 
         $line = sprintf("[%s]: %s\n", $date, $line);
-        $log_dir = null;
 
         // per-user logging is activated
         if (self::$instance && self::$instance->config->get('per_user_logging') && self::$instance->get_user_id()) {
@@ -1312,11 +1311,14 @@ class rcube
                 return false;
             }
         }
-        else if (!empty($log['dir'])) {
-            $log_dir = $log['dir'];
-        }
-        else if (self::$instance) {
-            $log_dir = self::$instance->config->get('log_dir');
+
+        if (empty($log_dir)) {
+            if (!empty($log['dir'])) {
+                $log_dir = $log['dir'];
+            }
+            else if (self::$instance) {
+                $log_dir = self::$instance->config->get('log_dir');
+            }
         }
 
         if (empty($log_dir)) {