diff --git a/.github/workflows/php.yml b/.github/workflows/php.yml
new file mode 100644
index 0000000..910b172
--- /dev/null
+++ b/.github/workflows/php.yml
@@ -0,0 +1,42 @@
+name: validate and test
+
+on:
+  push:
+    branches: [ "master" ]
+  pull_request:
+    branches: [ "master" ]
+
+permissions:
+  contents: read
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    
+    strategy:
+      matrix:
+        php-versions: ['8.0', '8.1' , '8.2' , '8.3']
+
+    steps:
+    - uses: actions/checkout@v3
+    
+    - name: Setup PHP
+      uses: shivammathur/setup-php@v2
+      with:
+        php-version: ${{ matrix.php-versions }}
+        extensions: xml
+
+    - name: Cache Composer packages
+      id: composer-cache
+      uses: actions/cache@v3
+      with:
+        path: vendor
+        key: ${{ runner.os }}-php-${{ hashFiles('**/composer.lock') }}
+        restore-keys: |
+          ${{ runner.os }}-php-
+
+    - name: Install dependencies
+      run: composer install
+
+    - name: Run test suite
+      run: composer run-script test
diff --git a/composer.json b/composer.json
index deaa659..b47675b 100644
--- a/composer.json
+++ b/composer.json
@@ -14,9 +14,12 @@
 		"ext-dom": "*"
 	},
 	"require-dev": {
-		"nette/tester": "~1.1.0"
+		"nette/tester": "^2.5"
 	},
 	"autoload": {
 		"classmap": ["src/Schematron.php"]
-	}
+	},
+	"scripts": {
+        "test": "tester -s tests"
+    }
 }
diff --git a/src/Schematron.php b/src/Schematron.php
index d4a725c..bda38f1 100644
--- a/src/Schematron.php
+++ b/src/Schematron.php
@@ -999,7 +999,7 @@ class SchematronXPath extends DOMXPath
 	/**
 	 * ($registerNodeNS is FALSE in opposition to DOMXPath default value)
 	 */
-	public function query($expression, DOMNode $context = NULL, $registerNodeNS = FALSE)
+	public function query($expression, DOMNode $context = NULL, $registerNodeNS = FALSE): mixed
 	{
 		return parent::query($expression, $context, $registerNodeNS);
 	}
@@ -1009,7 +1009,7 @@ public function query($expression, DOMNode $context = NULL, $registerNodeNS = FA
 	/**
 	 * ($registerNodeNS is FALSE in opposition to DOMXPath default value)
 	 */
-	public function evaluate($expression, DOMNode $context = NULL, $registerNodeNS = FALSE)
+	public function evaluate($expression, DOMNode $context = NULL, $registerNodeNS = FALSE): mixed
 	{
 		return parent::evaluate($expression, $context, $registerNodeNS);
 	}