diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
new file mode 100644
index 0000000..c92aa01
--- /dev/null
+++ b/.github/workflows/ci.yaml
@@ -0,0 +1,49 @@
+name: 'CI'
+
+on:
+  - 'push'
+  - 'pull_request'
+
+jobs:
+  tests:
+    name: 'Lint files'
+
+    runs-on: 'ubuntu-latest'
+
+    strategy:
+      matrix:
+        php-version:
+          - '5.3'
+          - '5.4'
+          - '5.5'
+          - '5.6'
+          - '7.0'
+          - '7.1'
+          - '7.2'
+          - '7.3'
+          - '7.4'
+          - '8.0'
+
+    steps:
+      - name: 'Check out'
+        uses: 'actions/checkout@v2'
+
+      - name: 'Set up PHP'
+        uses: 'shivammathur/setup-php@v2'
+        with:
+          php-version: '${{ matrix.php-version }}'
+          coverage: 'none'
+
+      - name: 'Get Composer cache directory'
+        id: 'composer-cache'
+        run: 'echo "::set-output name=cache-dir::$(composer config cache-files-dir)"'
+
+      - name: 'Cache dependencies'
+        uses: 'actions/cache@v2'
+        with:
+          path: '${{ steps.composer-cache.outputs.cache-dir }}'
+          key: "php-${{ matrix.php-version }}-composer-locked-${{ hashFiles('composer.lock') }}"
+          restore-keys: 'php-${{ matrix.php-version }}-composer-locked-'
+
+      - name: 'Lint PHP files'
+        run: 'find src -type f -name "*.php" -exec php -l {} \; | (! grep -v "No syntax errors detected" )'
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1cb6cc9..6f911a5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,12 @@
 CHANGELOG
 =========
 
+0.2.0
+-----
+
+* Added `StatementIdAlreadyExistsException`.
+* Added `UnsupportedStatementVersionException`.
+
 0.1.1
 -----
 
diff --git a/LICENSE b/LICENSE
index 967410f..00e1421 100644
--- a/LICENSE
+++ b/LICENSE
@@ -1,4 +1,4 @@
-Copyright (c) 2014-2016 Christian Flothmann
+Copyright (c) 2014-2018 Christian Flothmann
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
diff --git a/composer.json b/composer.json
index cc19a7c..976d964 100644
--- a/composer.json
+++ b/composer.json
@@ -24,7 +24,7 @@
     },
     "extra": {
         "branch-alias": {
-            "dev-master": "0.1.x-dev"
+            "dev-master": "0.2.x-dev"
         }
     }
 }
diff --git a/src/StatementIdAlreadyExistsException.php b/src/StatementIdAlreadyExistsException.php
new file mode 100644
index 0000000..9751ce6
--- /dev/null
+++ b/src/StatementIdAlreadyExistsException.php
@@ -0,0 +1,25 @@
+<?php
+
+/*
+ * This file is part of the xAPI package.
+ *
+ * (c) Christian Flothmann <christian.flothmann@xabbuh.de>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Xabbuh\XApi\Common\Exception;
+
+/**
+ * Statement id already exists exception.
+ *
+ * @author Jérôme Parmentier <jerome.parmentier@acensi.fr>
+ */
+class StatementIdAlreadyExistsException extends XApiException
+{
+    public function __construct($statementId, \Exception $previous = null)
+    {
+        parent::__construct(sprintf('A statement with ID "%s" already exists.', $statementId), 0, $previous);
+    }
+}
diff --git a/src/UnsupportedStatementVersionException.php b/src/UnsupportedStatementVersionException.php
new file mode 100644
index 0000000..19252a5
--- /dev/null
+++ b/src/UnsupportedStatementVersionException.php
@@ -0,0 +1,21 @@
+<?php
+
+/*
+ * This file is part of the xAPI package.
+ *
+ * (c) Christian Flothmann <christian.flothmann@xabbuh.de>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Xabbuh\XApi\Common\Exception;
+
+/**
+ * Unsupported statement version exception.
+ *
+ * @author Jérôme Parmentier <jerome.parmentier@acensi.fr>
+ */
+class UnsupportedStatementVersionException extends XApiException
+{
+}