diff --git a/README.md b/README.md
index 1faa4f5..fdc7136 100644
--- a/README.md
+++ b/README.md
@@ -10,6 +10,12 @@ This API client covers all functions of API V2 such as:
 
 If You want to send transactional messages in rich format please use new [API V3 client](https://github.com/FreshMail/php-api-client).
 
+## Installation via composer (compatible with PHP >=8.0)
+
+Add via composer:
+    
+    composer require freshmail/rest-api:^4.0
+
 ## Installation via composer (compatible with PHP >=7.0)
 
 Add via composer:
diff --git a/composer.json b/composer.json
index e9746c9..2593af0 100644
--- a/composer.json
+++ b/composer.json
@@ -31,12 +31,12 @@
         }
     ],
     "require": {
-        "php": ">=7.0",
+        "php": ">=7.0||^8.0",
         "ext-curl": "*",
         "ext-json": "*",
-        "psr/log": "^1.1",
-        "monolog/monolog": "^2",
-        "guzzlehttp/guzzle": "~7.2"
+        "psr/log": "^1.1|^2.0|^3.0",
+        "monolog/monolog": "^2.0|^3.0",
+        "guzzlehttp/guzzle": "~7.2|^7.3||^7.4"
     },
     "autoload": {
         "psr-4": {