diff --git a/src/MD_STD_SEC.php b/src/MD_STD_SEC.php
index a4bce73..7a3d8df 100644
--- a/src/MD_STD_SEC.php
+++ b/src/MD_STD_SEC.php
@@ -100,7 +100,7 @@ final class MD_STD_SEC {
         $loginLog['ip'][$hash_ip]['time'] = \time();
 
         // Update the log file
-        \file_put_contents($logfile_common, \json_encode($loginLog));
+        \file_put_contents($logfile_common, MD_STD::json_encode($loginLog));
 
         // Translate counters into delay multipliers
         $delay_multiplier_common = $loginLog['common']['count'];