diff --git a/.travis.yml b/.travis.yml
index 5ed27f0..74ccd1f 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -5,6 +5,9 @@ sudo: false
 php:
     - 7.2
     - 7.3
+    - 7.4
+    - 8.0
+    - 8.1
 
 matrix:
     fast_finish: true
diff --git a/composer.json b/composer.json
index 5f84391..a017ee2 100644
--- a/composer.json
+++ b/composer.json
@@ -5,18 +5,18 @@
     "license": "MIT",
     "bin": ["bin/rusty"],
     "require": {
-        "php": "^7.2",
+        "php": "^7.2|^8.0",
 
-        "symfony/process": "^4.4|^5.0",
-        "symfony/console": "^4.4|^5.0",
-        "symfony/finder": "^4.4|^5.0",
+        "symfony/process": "^4.4|^5.0|^6.0",
+        "symfony/console": "^4.4|^5.0|^6.0",
+        "symfony/finder": "^4.4|^5.0|^6.0",
 
-        "nikic/php-parser": "^3.0",
-        "league/commonmark": "^0.18,>=0.18.3",
+        "nikic/php-parser": "^3.0|*4.0",
+        "league/commonmark": "^0.19|^1.0",
         "gregwar/rst": "^1.0"
     },
     "require-dev": {
-        "phpunit/phpunit": "^7.0",
+        "phpunit/phpunit": "^7.0|^8.5|^9.5",
         "mikey179/vfsstream": "^1.6"
     },
     "autoload": {
diff --git a/tests/CodeSampleCompilerTest.php b/tests/CodeSampleCompilerTest.php
index 05e142b..bb58639 100644
--- a/tests/CodeSampleCompilerTest.php
+++ b/tests/CodeSampleCompilerTest.php
@@ -19,6 +19,14 @@ public function testItTransformsAssertCalls()
 require_once "/dir/file.php";
 \Rusty\Runtime\Asserter::assert('assert(42 === 42);', 42 === 42);
 CODE;
+        if (PHP_MAJOR_VERSION > 7) {
+            $expectedCode = <<<CODE
+<?php
+require_once "$runtimeNSDir/bootstrap.php";
+require_once "/dir/file.php";
+\Rusty\Runtime\Asserter::assert('assert(42 === 42)', 42 === 42);
+CODE;
+        }
 
         $compiler = new CodeSampleCompiler();
 
diff --git a/tests/Extractor/MarkdownTest.php b/tests/Extractor/MarkdownTest.php
index 8d8f93a..27bee05 100644
--- a/tests/Extractor/MarkdownTest.php
+++ b/tests/Extractor/MarkdownTest.php
@@ -29,7 +29,7 @@ public static function documents()
     /**
      * set up test environmemt
      */
-    public function setUp()
+    public function setUp(): void
     {
         $documents = self::documents();
 
diff --git a/tests/Extractor/RstTest.php b/tests/Extractor/RstTest.php
index 194d3ad..bfd8fdf 100644
--- a/tests/Extractor/RstTest.php
+++ b/tests/Extractor/RstTest.php
@@ -28,7 +28,7 @@ public static function documents()
     /**
      * set up test environmemt
      */
-    public function setUp()
+    public function setUp(): void
     {
         $documents = self::documents();
 
diff --git a/tests/Lint/PHPParserLinterTest.php b/tests/Lint/PHPParserLinterTest.php
index f4effb5..f38e617 100644
--- a/tests/Lint/PHPParserLinterTest.php
+++ b/tests/Lint/PHPParserLinterTest.php
@@ -32,10 +32,10 @@ public function validInputProvider()
 
     /**
      * @dataProvider invalidInputProvider
-     * @expectedException \Rusty\Lint\Exception\SyntaxError
      */
     public function testInvalidCodeThrowAnError(string $code)
     {
+        $this->expectException(\Rusty\Lint\Exception\SyntaxError::class);
         /** @var \SplFileInfo $splFileInfoMock */
         $splFileInfoMock = $this->createMock(\SplFileInfo::class);
         $sample = new CodeSample($splFileInfoMock, 42, $code);