diff --git a/php/composer.json b/php/composer.json
index c543c802..218bf4a7 100644
--- a/php/composer.json
+++ b/php/composer.json
@@ -11,7 +11,7 @@
         "slim/slim": "4.*",
         "php-di/slim-bridge": "^3.1",
         "guzzlehttp/guzzle": "^7.3",
-        "guzzlehttp/psr7": "^1.8",
+        "guzzlehttp/psr7": "^2.1",
         "http-interop/http-factory-guzzle": "^1.2",
         "slim/twig-view": "^3.2",
         "slim/csrf": "^1.2",
diff --git a/php/composer.lock b/php/composer.lock
index 69375bf9..8dd11464 100644
--- a/php/composer.lock
+++ b/php/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": "7559e80f58e2dd79a5e5799c144a3b6c",
+    "content-hash": "be1525e7f8659cfa807e1d5d548f6286",
     "packages": [
         {
             "name": "guzzlehttp/guzzle",
@@ -166,29 +166,32 @@
         },
         {
             "name": "guzzlehttp/psr7",
-            "version": "1.8.2",
+            "version": "2.1.0",
             "source": {
                 "type": "git",
                 "url": "https://github.com/guzzle/psr7.git",
-                "reference": "dc960a912984efb74d0a90222870c72c87f10c91"
+                "reference": "089edd38f5b8abba6cb01567c2a8aaa47cec4c72"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/guzzle/psr7/zipball/dc960a912984efb74d0a90222870c72c87f10c91",
-                "reference": "dc960a912984efb74d0a90222870c72c87f10c91",
+                "url": "https://api.github.com/repos/guzzle/psr7/zipball/089edd38f5b8abba6cb01567c2a8aaa47cec4c72",
+                "reference": "089edd38f5b8abba6cb01567c2a8aaa47cec4c72",
                 "shasum": ""
             },
             "require": {
-                "php": ">=5.4.0",
-                "psr/http-message": "~1.0",
-                "ralouphie/getallheaders": "^2.0.5 || ^3.0.0"
+                "php": "^7.2.5 || ^8.0",
+                "psr/http-factory": "^1.0",
+                "psr/http-message": "^1.0",
+                "ralouphie/getallheaders": "^3.0"
             },
             "provide": {
+                "psr/http-factory-implementation": "1.0",
                 "psr/http-message-implementation": "1.0"
             },
             "require-dev": {
-                "ext-zlib": "*",
-                "phpunit/phpunit": "~4.8.36 || ^5.7.27 || ^6.5.14 || ^7.5.20 || ^8.5.8 || ^9.3.10"
+                "bamarni/composer-bin-plugin": "^1.4.1",
+                "http-interop/http-factory-tests": "^0.9",
+                "phpunit/phpunit": "^8.5.8 || ^9.3.10"
             },
             "suggest": {
                 "laminas/laminas-httphandlerrunner": "Emit PSR-7 responses"
@@ -196,30 +199,53 @@
             "type": "library",
             "extra": {
                 "branch-alias": {
-                    "dev-master": "1.7-dev"
+                    "dev-master": "2.1-dev"
                 }
             },
             "autoload": {
                 "psr-4": {
                     "GuzzleHttp\\Psr7\\": "src/"
-                },
-                "files": [
-                    "src/functions_include.php"
-                ]
+                }
             },
             "notification-url": "https://packagist.org/downloads/",
             "license": [
                 "MIT"
             ],
             "authors": [
+                {
+                    "name": "Graham Campbell",
+                    "email": "hello@gjcampbell.co.uk",
+                    "homepage": "https://github.com/GrahamCampbell"
+                },
                 {
                     "name": "Michael Dowling",
                     "email": "mtdowling@gmail.com",
                     "homepage": "https://github.com/mtdowling"
                 },
+                {
+                    "name": "George Mponos",
+                    "email": "gmponos@gmail.com",
+                    "homepage": "https://github.com/gmponos"
+                },
+                {
+                    "name": "Tobias Nyholm",
+                    "email": "tobias.nyholm@gmail.com",
+                    "homepage": "https://github.com/Nyholm"
+                },
+                {
+                    "name": "Márk Sági-Kazár",
+                    "email": "mark.sagikazar@gmail.com",
+                    "homepage": "https://github.com/sagikazarmark"
+                },
                 {
                     "name": "Tobias Schultze",
+                    "email": "webmaster@tubo-world.de",
                     "homepage": "https://github.com/Tobion"
+                },
+                {
+                    "name": "Márk Sági-Kazár",
+                    "email": "mark.sagikazar@gmail.com",
+                    "homepage": "https://sagikazarmark.hu"
                 }
             ],
             "description": "PSR-7 message implementation that also provides common utility methods",
@@ -235,9 +261,23 @@
             ],
             "support": {
                 "issues": "https://github.com/guzzle/psr7/issues",
-                "source": "https://github.com/guzzle/psr7/tree/1.8.2"
+                "source": "https://github.com/guzzle/psr7/tree/2.1.0"
             },
-            "time": "2021-04-26T09:17:50+00:00"
+            "funding": [
+                {
+                    "url": "https://github.com/GrahamCampbell",
+                    "type": "github"
+                },
+                {
+                    "url": "https://github.com/Nyholm",
+                    "type": "github"
+                },
+                {
+                    "url": "https://tidelift.com/funding/github/packagist/guzzlehttp/psr7",
+                    "type": "tidelift"
+                }
+            ],
+            "time": "2021-10-06T17:43:30+00:00"
         },
         {
             "name": "http-interop/http-factory-guzzle",
@@ -1522,8 +1562,10 @@
     "prefer-lowest": false,
     "platform": {
         "ext-json": "*",
-        "ext-sodium": "*"
+        "ext-sodium": "*",
+        "ext-curl": "*",
+        "ext-apcu": "*"
     },
     "platform-dev": [],
-    "plugin-api-version": "2.0.0"
+    "plugin-api-version": "2.1.0"
 }