diff --git a/.php_cs.dist b/.php_cs.dist
index e4b62e2..fc1ac99 100644
--- a/.php_cs.dist
+++ b/.php_cs.dist
@@ -38,6 +38,7 @@ return PhpCsFixer\Config::create()
         'phpdoc_add_missing_param_annotation' => true,
         'phpdoc_order' => true,
         'semicolon_after_instruction' => true,
+        'single_line_throw' => false,
         'strict_comparison' => true,
         'strict_param' => true,
     ))
diff --git a/.travis.yml b/.travis.yml
index fdd0111..a913ea9 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -59,5 +59,10 @@ jobs:
         -
             <<: *STANDARD_TEST_JOB
             stage: Test
-            php: 7.3
+            php: 7.4
+
+        -
+            <<: *STANDARD_TEST_JOB
+            stage: Test
+            php: nightly
             env: COMPOSER_FLAGS="--ignore-platform-reqs"
diff --git a/composer.json b/composer.json
index 2d2eabb..da7b329 100644
--- a/composer.json
+++ b/composer.json
@@ -10,13 +10,13 @@
         }
     ],
     "require": {
-        "php": "^5.5.9 || ^7.0",
+        "php": "^5.6 || ^7.0 || ^8.0",
         "symfony/process": "^3.4 || ^4 || ^5"
     },
     "require-dev": {
-        "friendsofphp/php-cs-fixer": "^2.9",
+        "friendsofphp/php-cs-fixer": "^2.16",
         "maglnet/composer-require-checker": "^0.1.6",
-        "phpunit/phpunit": "^5.7.27 || ^6.5.8 || ^7.1",
+        "phpunit/phpunit": "^5.7.27 || ^6.5.8 || ^7.1 || ^8 || ^9",
         "symfony/phpunit-bridge": "^4.0 || ^5.0"
     },
     "config": {
diff --git a/tests/CommandExecutorTest.php b/tests/CommandExecutorTest.php
index 04e1c1e..9b42dd0 100644
--- a/tests/CommandExecutorTest.php
+++ b/tests/CommandExecutorTest.php
@@ -27,7 +27,11 @@ public function testSimpleExecution()
 
         $cliResult = $scriptExecutor->getResult();
 
-        $this->assertContains(basename(__FILE__), $cliResult->getOutput());
+        if (\is_callable([$this, 'assertStringContainsString'])) {
+            $this->assertStringContainsString(basename(__FILE__), $cliResult->getOutput());
+        } else {
+            $this->assertContains(basename(__FILE__), $cliResult->getOutput());
+        }
     }
 
     public function testSimpleExecutionWithArray()
@@ -36,6 +40,10 @@ public function testSimpleExecutionWithArray()
 
         $cliResult = $scriptExecutor->getResult();
 
-        $this->assertContains(basename(__FILE__), $cliResult->getOutput());
+        if (\is_callable([$this, 'assertStringContainsString'])) {
+            $this->assertStringContainsString(basename(__FILE__), $cliResult->getOutput());
+        } else {
+            $this->assertContains(basename(__FILE__), $cliResult->getOutput());
+        }
     }
 }
diff --git a/tests/ScriptExecutorTest.php b/tests/ScriptExecutorTest.php
index a5fd0d9..517adff 100644
--- a/tests/ScriptExecutorTest.php
+++ b/tests/ScriptExecutorTest.php
@@ -27,6 +27,10 @@ public function testSimpleExecution()
 
         $cliResult = $scriptExecutor->getResult();
 
-        $this->assertContains(basename(__FILE__), $cliResult->getOutput());
+        if (\is_callable([$this, 'assertStringContainsString'])) {
+            $this->assertStringContainsString(basename(__FILE__), $cliResult->getOutput());
+        } else {
+            $this->assertContains(basename(__FILE__), $cliResult->getOutput());
+        }
     }
 }