diff --git a/app/classes/VarExportor.php b/app/classes/VarExportor.php
index e73555b..c1352de 100644
--- a/app/classes/VarExportor.php
+++ b/app/classes/VarExportor.php
@@ -210,7 +210,7 @@ private function _formatVarAsJSON($var, $jsonService) {
 				case "MongoDate":
 					$timezone = @date_default_timezone_get();
 					date_default_timezone_set("UTC");
-					$this->_jsonParams[$this->_paramIndex] = "ISODate(\"" . date("Y-m-d", $var->sec) . "T" . date("H:i:s.", $var->sec) . ($var->usec/1000) . "Z\")";
+					$this->_jsonParams[$this->_paramIndex] = "ISODate(\"" . date("Y-m-d", $var->sec) . "T" . date("H:i:s.", $var->sec) . sprintf("%03d", $var->usec/1000) . "Z\")";
 					date_default_timezone_set($timezone);
 					return $this->_param($this->_paramIndex);
 				case "MongoTimestamp":