diff --git a/composer.json b/composer.json
index 73cd20f3d1..beff057bdf 100644
--- a/composer.json
+++ b/composer.json
@@ -31,7 +31,7 @@
         "erusev/parsedown" : "^1.7",
         "pimple/pimple" : "3.4.0",
         "psr/log": "~1.0",
-        "swiftmailer/swiftmailer" : "5.4.8",
+        "swiftmailer/swiftmailer" : "6.3.0",
         "symfony/console" : "4.2.12",
         "symfony/event-dispatcher" : "3.4.2",
         "gregwar/captcha": "1.1.9"