diff --git a/composer.lock b/composer.lock
index 4ece2d2..fad72c8 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "881383169f485b083c1b649beafbbe47",
+    "content-hash": "174ded36f2be3711a0a034b7ff8ea0eb",
     "packages": [
         {
             "name": "classpreloader/classpreloader",
@@ -1054,23 +1054,24 @@
         },
         {
             "name": "swiftmailer/swiftmailer",
-            "version": "v5.4.4",
+            "version": "v5.4.12",
             "source": {
                 "type": "git",
                 "url": "https://github.com/swiftmailer/swiftmailer.git",
-                "reference": "545ce9136690cea74f98f86fbb9c92dd9ab1a756"
+                "reference": "181b89f18a90f8925ef805f950d47a7190e9b950"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/swiftmailer/swiftmailer/zipball/545ce9136690cea74f98f86fbb9c92dd9ab1a756",
-                "reference": "545ce9136690cea74f98f86fbb9c92dd9ab1a756",
+                "url": "https://api.github.com/repos/swiftmailer/swiftmailer/zipball/181b89f18a90f8925ef805f950d47a7190e9b950",
+                "reference": "181b89f18a90f8925ef805f950d47a7190e9b950",
                 "shasum": ""
             },
             "require": {
                 "php": ">=5.3.3"
             },
             "require-dev": {
-                "mockery/mockery": "~0.9.1"
+                "mockery/mockery": "~0.9.1",
+                "symfony/phpunit-bridge": "~3.2"
             },
             "type": "library",
             "extra": {
@@ -1097,13 +1098,18 @@
                 }
             ],
             "description": "Swiftmailer, free feature-rich PHP mailer",
-            "homepage": "http://swiftmailer.org",
+            "homepage": "https://swiftmailer.symfony.com",
             "keywords": [
                 "email",
                 "mail",
                 "mailer"
             ],
-            "time": "2016-11-24T01:01:23+00:00"
+            "support": {
+                "issues": "https://github.com/swiftmailer/swiftmailer/issues",
+                "source": "https://github.com/swiftmailer/swiftmailer/tree/v5.4.12"
+            },
+            "abandoned": "symfony/mailer",
+            "time": "2018-07-31T09:26:32+00:00"
         },
         {
             "name": "symfony/console",
@@ -1944,5 +1950,5 @@
     "prefer-lowest": false,
     "platform": [],
     "platform-dev": [],
-    "plugin-api-version": "2.1.0"
+    "plugin-api-version": "2.6.0"
 }