diff --git a/CHANGELOG.md b/CHANGELOG.md
index b9c4e54..87fab26 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,12 @@
 
 All notable changes to `laravel-youtrack-sdk` will be documented in this file.
 
+## 4.0.0 - 2017-11-20
+
+### Changed
+
+- Updated YouTrack PHP SDK major version to 4.0.0
+
 ## 3.0.0 - 2017-09-13
 
 ### Changed
diff --git a/README.md b/README.md
index 945c65e..d9cfae7 100644
--- a/README.md
+++ b/README.md
@@ -30,7 +30,7 @@ Laravel wrapper for the [YouTrack PHP SDK](https://github.com/cybercog/youtrack-
 - [Contributing](#contributing)
 - [Testing](#testing)
 - [Security](#security)
-- [Credits](#credits)
+- [Contributors](#contributors)
 - [Alternatives](#alternatives)
 - [License](#license)
 - [About CyberCog](#about-cybercog)
@@ -243,11 +243,10 @@ $ composer test
 
 If you discover any security related issues, please email open@cybercog.su instead of using the issue tracker.
 
-## Credits
+## Contributors
 
-|  | @mention |
-|---|---|
-| ![@a-komarev](https://avatars2.githubusercontent.com/u/1849174?s=64) | [@a-komarev](https://github.com/a-komarev) |
+| <a href="https://github.com/a-komarev">![@a-komarev](https://avatars.githubusercontent.com/u/1849174?s=110)<br />Anton Komarev</a> |
+| :---: |
 
 [Laravel YouTrack SDK contributors list](../../contributors)
 
diff --git a/composer.json b/composer.json
index 33704fc..ff328b0 100644
--- a/composer.json
+++ b/composer.json
@@ -38,7 +38,7 @@
     },
     "require": {
         "php": "^7.1",
-        "cybercog/youtrack-php-sdk": "^3.0",
+        "cybercog/youtrack-php-sdk": "^4.0",
         "illuminate/support": "~5.1.20|~5.2|~5.3|~5.4|~5.5"
     },
     "require-dev": {
@@ -60,13 +60,15 @@
             "composer install --prefer-dist --no-interaction --working-dir tests/framework/5.1",
             "composer install --prefer-dist --no-interaction --working-dir tests/framework/5.2",
             "composer install --prefer-dist --no-interaction --working-dir tests/framework/5.3",
-            "composer install --prefer-dist --no-interaction --working-dir tests/framework/5.4"
+            "composer install --prefer-dist --no-interaction --working-dir tests/framework/5.4",
+            "composer install --prefer-dist --no-interaction --working-dir tests/framework/5.5"
         ],
         "test": [
             "./vendor/bin/phpunit --configuration tests/framework/5.1",
             "./vendor/bin/phpunit --configuration tests/framework/5.2",
             "./vendor/bin/phpunit --configuration tests/framework/5.3",
-            "./vendor/bin/phpunit --configuration tests/framework/5.4"
+            "./vendor/bin/phpunit --configuration tests/framework/5.4",
+            "./vendor/bin/phpunit --configuration tests/framework/5.5"
         ]
     },
     "config": {
diff --git a/tests/framework/5.5/composer.json b/tests/framework/5.5/composer.json
new file mode 100644
index 0000000..52a9594
--- /dev/null
+++ b/tests/framework/5.5/composer.json
@@ -0,0 +1,8 @@
+{
+    "require": {
+        "illuminate/support": "~5.5.0"
+    },
+    "require-dev": {
+        "orchestra/testbench": "3.5.*"
+    }
+}
diff --git a/tests/framework/5.5/phpunit.xml.dist b/tests/framework/5.5/phpunit.xml.dist
new file mode 100644
index 0000000..16d3581
--- /dev/null
+++ b/tests/framework/5.5/phpunit.xml.dist
@@ -0,0 +1,31 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<phpunit
+    backupGlobals="false"
+    backupStaticAttributes="false"
+    bootstrap="vendor/autoload.php"
+    colors="true"
+    convertErrorsToExceptions="true"
+    convertNoticesToExceptions="true"
+    convertWarningsToExceptions="true"
+    processIsolation="false"
+    stopOnFailure="false"
+    syntaxCheck="false">
+    <testsuites>
+        <testsuite name="Package">
+            <directory suffix="Test.php">../../Unit/</directory>
+        </testsuite>
+    </testsuites>
+    <filter>
+        <whitelist>
+            <directory suffix=".php">./src/</directory>
+        </whitelist>
+    </filter>
+    <php>
+        <env name="YOUTRACK_BASE_URI" value="https://youtrack.example.com"/>
+        <env name="YOUTRACK_AUTH" value="token"/>
+        <env name="YOUTRACK_TOKEN" value=""/>
+        <env name="YOUTRACK_USERNAME" value=""/>
+        <env name="YOUTRACK_PASSWORD" value=""/>
+        <env name="YOUTRACK_PROJECT" value="TEST"/>
+    </php>
+</phpunit>