diff --git a/composer.json b/composer.json
index 176b0347..6f51456d 100644
--- a/composer.json
+++ b/composer.json
@@ -44,7 +44,7 @@
         "textalk/websocket": "^1.5",
         "twig/twig": "^3.3",
         "vimeo/psalm": "^4.7.2",
-        "vlucas/phpdotenv": "^5.0",
+        "vlucas/phpdotenv": "^5.3",
         "webonyx/graphql-php": "^14.9"
     },
     "autoload": {
diff --git a/composer.lock b/composer.lock
index 94940612..b5d19ee4 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": "cfd4b326652ed5baa441a2732435fe5f",
+    "content-hash": "164d38cce170c6d0a11a0da801b434a2",
     "packages": [],
     "packages-dev": [
         {
@@ -6768,31 +6768,31 @@
         },
         {
             "name": "vlucas/phpdotenv",
-            "version": "v5.3.0",
+            "version": "v5.3.1",
             "source": {
                 "type": "git",
                 "url": "https://github.com/vlucas/phpdotenv.git",
-                "reference": "b3eac5c7ac896e52deab4a99068e3f4ab12d9e56"
+                "reference": "accaddf133651d4b5cf81a119f25296736ffc850"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/vlucas/phpdotenv/zipball/b3eac5c7ac896e52deab4a99068e3f4ab12d9e56",
-                "reference": "b3eac5c7ac896e52deab4a99068e3f4ab12d9e56",
+                "url": "https://api.github.com/repos/vlucas/phpdotenv/zipball/accaddf133651d4b5cf81a119f25296736ffc850",
+                "reference": "accaddf133651d4b5cf81a119f25296736ffc850",
                 "shasum": ""
             },
             "require": {
                 "ext-pcre": "*",
-                "graham-campbell/result-type": "^1.0.1",
+                "graham-campbell/result-type": "^1.0.2",
                 "php": "^7.1.3 || ^8.0",
-                "phpoption/phpoption": "^1.7.4",
-                "symfony/polyfill-ctype": "^1.17",
-                "symfony/polyfill-mbstring": "^1.17",
-                "symfony/polyfill-php80": "^1.17"
+                "phpoption/phpoption": "^1.8",
+                "symfony/polyfill-ctype": "^1.23",
+                "symfony/polyfill-mbstring": "^1.23.1",
+                "symfony/polyfill-php80": "^1.23.1"
             },
             "require-dev": {
                 "bamarni/composer-bin-plugin": "^1.4.1",
                 "ext-filter": "*",
-                "phpunit/phpunit": "^7.5.20 || ^8.5.14 || ^9.5.1"
+                "phpunit/phpunit": "^7.5.20 || ^8.5.21 || ^9.5.10"
             },
             "suggest": {
                 "ext-filter": "Required to use the boolean validator."
@@ -6815,13 +6815,11 @@
             "authors": [
                 {
                     "name": "Graham Campbell",
-                    "email": "graham@alt-three.com",
-                    "homepage": "https://gjcampbell.co.uk/"
+                    "email": "hello@gjcampbell.co.uk"
                 },
                 {
                     "name": "Vance Lucas",
-                    "email": "vance@vancelucas.com",
-                    "homepage": "https://vancelucas.com/"
+                    "email": "vance@vancelucas.com"
                 }
             ],
             "description": "Loads environment variables from `.env` to `getenv()`, `$_ENV` and `$_SERVER` automagically.",
@@ -6832,7 +6830,7 @@
             ],
             "support": {
                 "issues": "https://github.com/vlucas/phpdotenv/issues",
-                "source": "https://github.com/vlucas/phpdotenv/tree/v5.3.0"
+                "source": "https://github.com/vlucas/phpdotenv/tree/v5.3.1"
             },
             "funding": [
                 {
@@ -6844,7 +6842,7 @@
                     "type": "tidelift"
                 }
             ],
-            "time": "2021-01-20T15:23:13+00:00"
+            "time": "2021-10-02T19:24:42+00:00"
         },
         {
             "name": "webimpress/safe-writer",