diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index bfbad11..8ab4cff 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -8,7 +8,7 @@ jobs:
 
     strategy:
       matrix:
-        php: [7.1, 7.2, 7.3, 7.4, 8.0]
+        php: [7.4, 8.0, 8.1]
 
     steps:
     - name: Checkout code
diff --git a/composer.json b/composer.json
index 1864faf..6289b08 100644
--- a/composer.json
+++ b/composer.json
@@ -15,7 +15,7 @@
 	],
 	"minimum-stability": "RC",
 	"require": {
-		"php": "^7.1 || ^8.0",
+		"php": "^7.4 || ^8.0",
 		"codeception/codeception": "*@dev",
 		"symfony/finder": ">=3.4 <6.0"
 	},
diff --git a/readme.md b/readme.md
index 937e409..eb095a0 100644
--- a/readme.md
+++ b/readme.md
@@ -9,7 +9,7 @@ A Codeception module for testing local filesystem.
 
 ## Requirements
 
-* `PHP 7.1` or higher.
+* `PHP 7.4` or higher.
 
 ## Installation
 
diff --git a/src/Codeception/Module/Filesystem.php b/src/Codeception/Module/Filesystem.php
index 7268389..33d5606 100644
--- a/src/Codeception/Module/Filesystem.php
+++ b/src/Codeception/Module/Filesystem.php
@@ -4,11 +4,13 @@
 
 namespace Codeception\Module;
 
-use Codeception\Util\FileSystem as Util;
-use Symfony\Component\Finder\Finder;
+use Codeception\Configuration;
 use Codeception\Module;
+use Codeception\PHPUnit\TestCase;
 use Codeception\TestInterface;
-use Codeception\Configuration;
+use Codeception\Util\FileSystem as Util;
+use PHPUnit\Framework\AssertionFailedError;
+use Symfony\Component\Finder\Finder;
 
 /**
  * Module for testing local filesystem.
@@ -24,16 +26,11 @@
  */
 class Filesystem extends Module
 {
-    protected $file;
-    /**
-     * @var string|null
-     */
-    protected $filepath;
+    protected string $file = '';
 
-    /**
-     * @var string
-     */
-    protected $path = '';
+    protected string $filePath = '';
+
+    protected string $path = '';
 
     public function _before(TestInterface $test): void
     {
@@ -56,6 +53,7 @@ protected function absolutizePath(string $path): string
         if (strpos($path, '/') === 0) {
             return $path;
         }
+
         // windows
         if (strpos($path, ':\\') === 1) {
             return $path;
@@ -78,7 +76,7 @@ protected function absolutizePath(string $path): string
     public function openFile(string $filename): void
     {
         $this->file = file_get_contents($this->absolutizePath($filename));
-        $this->filepath = $filename;
+        $this->filePath = $filename;
     }
 
     /**
@@ -92,8 +90,9 @@ public function openFile(string $filename): void
     public function deleteFile(string $filename): void
     {
         if (!file_exists($this->absolutizePath($filename))) {
-            \Codeception\PHPUnit\TestCase::fail('file not found');
+            TestCase::fail('file not found');
         }
+
         unlink($this->absolutizePath($filename));
     }
 
@@ -162,6 +161,7 @@ public function seeNumberNewLines(int $number): void
             "The number of new lines does not match with {$number}"
         );
     }
+
     /**
      * Checks that contents of currently opened file matches $regex
      */
@@ -185,7 +185,7 @@ public function seeThisFileMatches(string $regex): void
     public function seeFileContentsEqual(string $text): void
     {
         $file = str_replace("\r", '', $this->file);
-        \Codeception\PHPUnit\TestCase::assertEquals($text, $file);
+        TestCase::assertEquals($text, $file);
     }
 
     /**
@@ -207,7 +207,7 @@ public function dontSeeInThisFile(string $text): void
      */
     public function deleteThisFile(): void
     {
-        $this->deleteFile($this->filepath);
+        $this->deleteFile($this->filePath);
     }
 
     /**
@@ -223,7 +223,7 @@ public function seeFileFound(string $filename, string $path = ''): void
     {
         if ($path === '' && file_exists($filename)) {
             $this->openFile($filename);
-            \Codeception\PHPUnit\TestCase::assertFileExists($filename);
+            TestCase::assertFileExists($filename);
             return;
         }
 
@@ -234,7 +234,7 @@ public function seeFileFound(string $filename, string $path = ''): void
         }
 
         $this->openFile($found);
-        \Codeception\PHPUnit\TestCase::assertFileExists($found);
+        TestCase::assertFileExists($found);
     }
 
     /**
@@ -243,7 +243,7 @@ public function seeFileFound(string $filename, string $path = ''): void
     public function dontSeeFileFound(string $filename, string $path = ''): void
     {
         if ($path === '') {
-            \Codeception\PHPUnit\TestCase::assertFileNotExists($filename);
+            TestCase::assertFileDoesNotExist($filename);
             return;
         }
 
@@ -251,17 +251,17 @@ public function dontSeeFileFound(string $filename, string $path = ''): void
 
         if ($found === false) {
             //this line keeps a count of assertions correct
-            \Codeception\PHPUnit\TestCase::assertTrue(true);
+            TestCase::assertTrue(true);
             return;
         }
 
-        \Codeception\PHPUnit\TestCase::assertFileNotExists($found);
+        TestCase::assertFileDoesNotExist($found);
     }
 
     /**
      * Finds the first matching file
      *
-     * @throws \PHPUnit\Framework\AssertionFailedError When path does not exist
+     * @throws AssertionFailedError When path does not exist
      * @return string|false Path to the first matching file
      */
     private function findFileInPath(string $filename, string $path)
diff --git a/tests/unit/Codeception/Module/FilesystemTest.php b/tests/unit/Codeception/Module/FilesystemTest.php
index e3bc481..a077630 100644
--- a/tests/unit/Codeception/Module/FilesystemTest.php
+++ b/tests/unit/Codeception/Module/FilesystemTest.php
@@ -2,24 +2,23 @@
 
 declare(strict_types=1);
 
+use Codeception\Lib\ModuleContainer;
 use Codeception\Module\Filesystem;
+use Codeception\PHPUnit\TestCase;
 use Codeception\Stub;
 use PHPUnit\Framework\AssertionFailedError;
 
 if (!function_exists('make_container')) {
     function make_container()
     {
-        return Stub::make(\Codeception\Lib\ModuleContainer::class);
+        return Stub::make(ModuleContainer::class);
     }
 }
 
-final class FilesystemTest extends \Codeception\PHPUnit\TestCase
+final class FilesystemTest extends TestCase
 {
 
-    /**
-     * @var \Codeception\Module\Filesystem
-     */
-    protected $module;
+    protected ?Filesystem $module = null;
 
     public function _setUp()
     {