diff --git a/.github/workflows/unit-tests.yaml b/.github/workflows/unit-tests.yaml
new file mode 100644
index 000000000..c00148dfd
--- /dev/null
+++ b/.github/workflows/unit-tests.yaml
@@ -0,0 +1,37 @@
+on:
+    - push
+    - pull_request
+
+jobs:
+    phpunit:
+        runs-on: ubuntu-latest
+
+        strategy:
+            matrix:
+                php:
+                    - '7.1'
+                    - '7.2'
+                    - '7.3'
+                    - '7.4'
+                    - '8.0'
+                    - '8.1'
+                    - '8.2'
+                    - '8.3'
+                    - '8.4'
+
+        steps:
+            - name: Checkout the source code
+              uses: actions/checkout@v4
+
+            - name: Set up PHP
+              uses: shivammathur/setup-php@v2
+              with:
+                  php-version: '${{ matrix.php }}'
+
+            - name: Install dependencies
+              run: composer install
+
+            - name: Run tests
+              run: |
+                  vendor/bin/phpunit
+                  vendor/bin/phpunit test/CommonMarkTestWeak.php || true
diff --git a/.gitignore b/.gitignore
index d8a7996ab..47342dc5e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,3 @@
 composer.lock
 vendor/
+.phpunit.result.cache
diff --git a/.travis.yml b/.travis.yml
deleted file mode 100644
index e1f556b1b..000000000
--- a/.travis.yml
+++ /dev/null
@@ -1,30 +0,0 @@
-language: php
-
-matrix:
-  include:
-    - php: 5.3
-      dist: precise
-    - php: 5.4
-      dist: trusty
-    - php: 5.5
-      dist: trusty
-    - php: 5.6
-      dist: xenial
-    - php: 7.0
-      dist: xenial
-    - php: 7.1
-      dist: bionic
-    - php: 7.2
-      dist: bionic
-    - php: 7.3
-      dist: bionic
-    - php: 7.4
-      dist: bionic
-
-install:
-  - composer install --prefer-dist --no-interaction --no-progress
-
-script:
-  - vendor/bin/phpunit
-  - vendor/bin/phpunit test/CommonMarkTestWeak.php || true
-  - '[ -z "$TRAVIS_TAG" ] || [ "$TRAVIS_TAG" == "$(php -r "require(\"Parsedown.php\"); echo Parsedown::version;")" ]'
diff --git a/composer.json b/composer.json
index f8b40f8ce..b145680a2 100644
--- a/composer.json
+++ b/composer.json
@@ -13,11 +13,11 @@
         }
     ],
     "require": {
-        "php": ">=5.3.0",
+        "php": ">=7.1",
         "ext-mbstring": "*"
     },
     "require-dev": {
-        "phpunit/phpunit": "^4.8.35"
+        "phpunit/phpunit": "^7.5|^8.5|^9.6"
     },
     "autoload": {
         "psr-0": {"Parsedown": ""}
diff --git a/test/CommonMarkTestStrict.php b/test/CommonMarkTestStrict.php
index 3837738cb..4aa26dcfb 100644
--- a/test/CommonMarkTestStrict.php
+++ b/test/CommonMarkTestStrict.php
@@ -1,17 +1,19 @@
 <?php
 
+use PHPUnit\Framework\TestCase;
+
 /**
  * Test Parsedown against the CommonMark spec
  *
  * @link http://commonmark.org/ CommonMark
  */
-class CommonMarkTestStrict extends PHPUnit_Framework_TestCase
+class CommonMarkTestStrict extends TestCase
 {
     const SPEC_URL = 'https://raw.githubusercontent.com/jgm/CommonMark/master/spec.txt';
 
     protected $parsedown;
 
-    protected function setUp()
+    protected function setUp() : void
     {
         $this->parsedown = new TestParsedown();
         $this->parsedown->setUrlsLinked(false);
diff --git a/test/CommonMarkTestWeak.php b/test/CommonMarkTestWeak.php
index ef4081aa1..8d0bb4ab2 100644
--- a/test/CommonMarkTestWeak.php
+++ b/test/CommonMarkTestWeak.php
@@ -17,7 +17,7 @@ class CommonMarkTestWeak extends CommonMarkTestStrict
 {
     protected $textLevelElementRegex;
 
-    protected function setUp()
+    protected function setUp() : void
     {
         parent::setUp();
 
diff --git a/test/data/fenced_code_block.html b/test/data/fenced_code_block.html
index 50d39df22..8ef93ae7e 100644
--- a/test/data/fenced_code_block.html
+++ b/test/data/fenced_code_block.html
@@ -15,4 +15,6 @@
 <pre><code>foo
 
 
-bar</code></pre>
\ No newline at end of file
+bar</code></pre>
+<pre><code class="language-php">&lt;?php
+echo "Hello World";</code></pre>
\ No newline at end of file
diff --git a/test/data/fenced_code_block.md b/test/data/fenced_code_block.md
index 3e4155a88..81ca2bae9 100644
--- a/test/data/fenced_code_block.md
+++ b/test/data/fenced_code_block.md
@@ -35,4 +35,9 @@ foo
 
 
 bar
+```
+
+```php some-class
+<?php
+echo "Hello World";
 ```
\ No newline at end of file