diff --git a/composer.json b/composer.json
index 54e2e70c..bb925613 100644
--- a/composer.json
+++ b/composer.json
@@ -13,7 +13,7 @@
         "league/event": "2.1.*",
         "symfony/ldap": "3.4.7",
         "symfony/var-dumper": "3.4.7",
-        "zendframework/zend-diactoros" : "1.4.*",
+        "zendframework/zend-diactoros" : "1.8.*",
         "appserver-io-psr/di": "3.0.*",
         "appserver-io-psr/epb": "7.0.*",
         "appserver-io-psr/pms": "2.0.*",
diff --git a/composer.lock b/composer.lock
index 19f66bf4..0b6a4c8b 100644
--- a/composer.lock
+++ b/composer.lock
@@ -1,10 +1,10 @@
 {
     "_readme": [
         "This file locks the dependencies of your project to a known state",
-        "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#composer-lock-the-lock-file",
+        "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "36695d0e19d8244b04368d15deda4f45",
+    "content-hash": "8c2d98966ab0a4d071847e31951fe7f8",
     "packages": [
         {
             "name": "appserver-io-psr/application",
@@ -4044,6 +4044,9 @@
                 "request",
                 "response"
             ],
+            "support": {
+                "source": "https://github.com/php-fig/http-message/tree/master"
+            },
             "time": "2016-08-06T14:39:51+00:00"
         },
         {
@@ -5306,21 +5309,21 @@
         },
         {
             "name": "zendframework/zend-diactoros",
-            "version": "1.4.1",
+            "version": "1.8.4",
             "source": {
                 "type": "git",
                 "url": "https://github.com/zendframework/zend-diactoros.git",
-                "reference": "424a840dc3bedcdeea510b42e056c77c2d6c4bef"
+                "reference": "736ffa7c2bfa4a60e8a10acb316fa2ac456c5fba"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/zendframework/zend-diactoros/zipball/424a840dc3bedcdeea510b42e056c77c2d6c4bef",
-                "reference": "424a840dc3bedcdeea510b42e056c77c2d6c4bef",
+                "url": "https://api.github.com/repos/zendframework/zend-diactoros/zipball/736ffa7c2bfa4a60e8a10acb316fa2ac456c5fba",
+                "reference": "736ffa7c2bfa4a60e8a10acb316fa2ac456c5fba",
                 "shasum": ""
             },
             "require": {
-                "php": "^5.4 || ^7.0",
-                "psr/http-message": "~1.0"
+                "php": "^5.6 || ^7.0",
+                "psr/http-message": "^1.0"
             },
             "provide": {
                 "psr/http-message-implementation": "1.0"
@@ -5328,17 +5331,28 @@
             "require-dev": {
                 "ext-dom": "*",
                 "ext-libxml": "*",
-                "phpunit/phpunit": "^4.6 || ^5.5",
-                "zendframework/zend-coding-standard": "~1.0.0"
+                "phpunit/phpunit": "^5.7.16 || ^6.0.8 || ^7.2.7",
+                "zendframework/zend-coding-standard": "~1.0"
             },
             "type": "library",
             "extra": {
                 "branch-alias": {
-                    "dev-master": "1.4-dev",
-                    "dev-develop": "1.5-dev"
+                    "dev-master": "1.8.x-dev",
+                    "dev-develop": "1.9.x-dev",
+                    "dev-release-2.0": "2.0.x-dev"
                 }
             },
             "autoload": {
+                "files": [
+                    "src/functions/create_uploaded_file.php",
+                    "src/functions/marshal_headers_from_sapi.php",
+                    "src/functions/marshal_method_from_sapi.php",
+                    "src/functions/marshal_protocol_version_from_sapi.php",
+                    "src/functions/marshal_uri_from_sapi.php",
+                    "src/functions/normalize_server.php",
+                    "src/functions/normalize_uploaded_files.php",
+                    "src/functions/parse_cookie_header.php"
+                ],
                 "psr-4": {
                     "Zend\\Diactoros\\": "src/"
                 }
@@ -5354,8 +5368,12 @@
                 "psr",
                 "psr-7"
             ],
+            "support": {
+                "issues": "https://github.com/zendframework/zend-diactoros/issues",
+                "source": "https://github.com/zendframework/zend-diactoros"
+            },
             "abandoned": "laminas/laminas-diactoros",
-            "time": "2017-08-17T21:21:00+00:00"
+            "time": "2018-08-01T13:47:49+00:00"
         }
     ],
     "packages-dev": [
@@ -5403,7 +5421,7 @@
             "keywords": [
                 "php application server linux debian build"
             ],
-            "time": "2021-04-30 09:41:02"
+            "time": "2021-04-30T09:41:02+00:00"
         },
         {
             "name": "appserver-io/build",
@@ -8976,5 +8994,6 @@
     "platform": {
         "php": ">=5.5.0 < 7.0.0"
     },
-    "platform-dev": []
+    "platform-dev": [],
+    "plugin-api-version": "2.3.0"
 }