diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 8de10b6..a2ad122 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -8,7 +8,7 @@ jobs:
 
     strategy:
       matrix:
-        php: [7.3, 7.4, 8.0]
+        php: [7.4, 8.0, 8.1]
 
     steps:
     - name: Checkout code
diff --git a/README.md b/README.md
index 17977bd..5d6e9a1 100644
--- a/README.md
+++ b/README.md
@@ -15,7 +15,7 @@ With [BDD][3] assertions influenced by [Chai][4], [Jasmine][5], and [RSpec][6] y
 
 ## Installation
 
-*Requires PHP  7.1 or higher*
+*Requires PHP  7.4 or higher*
 
 ```
 composer require codeception/verify --dev
diff --git a/composer.json b/composer.json
index d92de84..6fa23f2 100644
--- a/composer.json
+++ b/composer.json
@@ -13,7 +13,7 @@
         }
     ],
     "require": {
-        "php": "^7.3 || ^8.0",
+        "php": "^7.4 || ^8.0",
         "ext-dom": "*",
         "phpunit/phpunit": "^9.3"
     },
diff --git a/src/Codeception/Exception/InvalidVerifyException.php b/src/Codeception/Exception/InvalidVerifyException.php
index f04fd07..c8a7a45 100644
--- a/src/Codeception/Exception/InvalidVerifyException.php
+++ b/src/Codeception/Exception/InvalidVerifyException.php
@@ -1,4 +1,6 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace Codeception\Exception;
 
diff --git a/src/Codeception/Verify/Asserts/AssertThrows.php b/src/Codeception/Verify/Asserts/AssertThrows.php
index 76b81b1..02462fd 100644
--- a/src/Codeception/Verify/Asserts/AssertThrows.php
+++ b/src/Codeception/Verify/Asserts/AssertThrows.php
@@ -1,4 +1,6 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace Codeception\Verify\Asserts;
 
@@ -18,23 +20,23 @@ public function assertThrows($throws = null, $message = false): self
 
         try {
             call_user_func($this->actual);
-        } catch (Throwable $exception) {
+        } catch (Throwable $throwable) {
             if (!$throws) {
                 return $this; // it throws
             }
 
-            $actualThrows = get_class($exception);
-            $actualMessage = $exception->getMessage();
+            $actualThrows = get_class($throwable);
+            $actualMessage = $throwable->getMessage();
 
-            Assert::assertSame($throws, $actualThrows, sprintf('exception \'%s\' was expected, but \'%s\' was thrown', $throws, $actualThrows));
+            Assert::assertSame($throws, $actualThrows, sprintf("exception '%s' was expected, but '%s' was thrown", $throws, $actualThrows));
 
             if ($message) {
-                Assert::assertSame($message, $actualMessage, sprintf('exception message \'%s\' was expected, but \'%s\' was received', $message, $actualMessage));
+                Assert::assertSame($message, $actualMessage, sprintf("exception message '%s' was expected, but '%s' was received", $message, $actualMessage));
             }
         }
 
-        if (!isset($exception)) {
-            throw new ExpectationFailedException(sprintf('exception \'%s\' was not thrown as expected', $throws));
+        if (!isset($throwable)) {
+            throw new ExpectationFailedException(sprintf("exception '%s' was not thrown as expected", $throws));
         }
 
         return $this;
@@ -62,11 +64,11 @@ public function assertDoesNotThrow($throws = null, $message = false): self
             }
 
             if (!$message) {
-                throw new ExpectationFailedException(sprintf('exception \'%s\' was not expected to be thrown', $throws));
+                throw new ExpectationFailedException(sprintf("exception '%s' was not expected to be thrown", $throws));
             }
 
             if ($message === $actualMessage) {
-                throw new ExpectationFailedException(sprintf('exception \'%s\' with message \'%s\' was not expected to be thrown', $throws, $message));
+                throw new ExpectationFailedException(sprintf("exception '%s' with message '%s' was not expected to be thrown", $throws, $message));
             }
         }
 
diff --git a/src/Codeception/Verify/Expect.php b/src/Codeception/Verify/Expect.php
index d20f0fe..8cda466 100644
--- a/src/Codeception/Verify/Expect.php
+++ b/src/Codeception/Verify/Expect.php
@@ -1,4 +1,6 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace Codeception\Verify;
 
diff --git a/src/Codeception/Verify/Expectations/ExpectAny.php b/src/Codeception/Verify/Expectations/ExpectAny.php
index 3fd22b8..9bbc582 100644
--- a/src/Codeception/Verify/Expectations/ExpectAny.php
+++ b/src/Codeception/Verify/Expectations/ExpectAny.php
@@ -1,4 +1,6 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace Codeception\Verify\Expectations;
 
@@ -18,19 +20,19 @@ public function arrayToContainEqual($needle, string $message = ''): self
         return $this;
     }
 
-    public function arrayToContainOnly($type, $isNativeType = null, string $message = ''): self
+    public function arrayToContainOnly(string $type, ?bool $isNativeType = null, string $message = ''): self
     {
         Expect::Array($this->actual)->toContainOnly($type, $isNativeType, $message);
         return $this;
     }
 
-    public function arrayToContainOnlyInstancesOf($className, string $message = ''): self
+    public function arrayToContainOnlyInstancesOf(string $className, string $message = ''): self
     {
         Expect::Array($this->actual)->toContainOnlyInstancesOf($className, $message);
         return $this;
     }
 
-    public function arrayToHaveCount($expectedCount, string $message = ''): self
+    public function arrayToHaveCount(int $expectedCount, string $message = ''): self
     {
         Expect::Array($this->actual)->toHaveCount($expectedCount, $message);
         return $this;
@@ -60,13 +62,13 @@ public function arrayNotToContainEqual($needle, string $message = ''): self
         return $this;
     }
 
-    public function arrayNotToContainOnly($type, $isNativeType = null, string $message = ''): self
+    public function arrayNotToContainOnly(string $type, ?bool $isNativeType = null, string $message = ''): self
     {
         Expect::Array($this->actual)->notToContainOnly($type, $isNativeType, $message);
         return $this;
     }
 
-    public function arrayNotToHaveCount($expectedCount, string $message = ''): self
+    public function arrayNotToHaveCount(int $expectedCount, string $message = ''): self
     {
         Expect::Array($this->actual)->notToHaveCount($expectedCount, $message);
         return $this;
@@ -84,13 +86,13 @@ public function arrayToHaveSameSizeAs($expected, string $message = ''): self
         return $this;
     }
 
-    public function baseObjectToHaveAttribute($attributeName, string $message = ''): self
+    public function baseObjectToHaveAttribute(string $attributeName, string $message = ''): self
     {
         Expect::BaseObject($this->actual)->toHaveAttribute($attributeName, $message);
         return $this;
     }
 
-    public function baseObjectNotToHaveAttribute($attributeName, string $message = ''): self
+    public function baseObjectNotToHaveAttribute(string $attributeName, string $message = ''): self
     {
         Expect::BaseObject($this->actual)->notToHaveAttribute($attributeName, $message);
         return $this;
@@ -108,25 +110,25 @@ public function callableNotToThrow($throws = null, string $message = ''): self
         return $this;
     }
 
-    public function classToHaveAttribute($attributeName, string $message = ''): self
+    public function classToHaveAttribute(string $attributeName, string $message = ''): self
     {
         Expect::Class($this->actual)->toHaveAttribute($attributeName, $message);
         return $this;
     }
 
-    public function classToHaveStaticAttribute($attributeName, string $message = ''): self
+    public function classToHaveStaticAttribute(string $attributeName, string $message = ''): self
     {
         Expect::Class($this->actual)->toHaveStaticAttribute($attributeName, $message);
         return $this;
     }
 
-    public function classNotToHaveAttribute($attributeName, string $message = ''): self
+    public function classNotToHaveAttribute(string $attributeName, string $message = ''): self
     {
         Expect::Class($this->actual)->notToHaveAttribute($attributeName, $message);
         return $this;
     }
 
-    public function classNotToHaveStaticAttribute($attributeName, string $message = ''): self
+    public function classNotToHaveStaticAttribute(string $attributeName, string $message = ''): self
     {
         Expect::Class($this->actual)->notToHaveStaticAttribute($attributeName, $message);
         return $this;
@@ -174,19 +176,19 @@ public function fileNotToExist(string $message = ''): self
         return $this;
     }
 
-    public function fileToBeEqual($expected, string $message = ''): self
+    public function fileToBeEqual(string $expected, string $message = ''): self
     {
         Expect::File($this->actual)->toBeEqual($expected, $message);
         return $this;
     }
 
-    public function fileToBeEqualCanonicalizing($expected, string $message = ''): self
+    public function fileToBeEqualCanonicalizing(string $expected, string $message = ''): self
     {
         Expect::File($this->actual)->toBeEqualCanonicalizing($expected, $message);
         return $this;
     }
 
-    public function fileToBeEqualIgnoringCase($expected, string $message = ''): self
+    public function fileToBeEqualIgnoringCase(string $expected, string $message = ''): self
     {
         Expect::File($this->actual)->toBeEqualIgnoringCase($expected, $message);
         return $this;
@@ -222,61 +224,61 @@ public function fileToBeWritable(string $message = ''): self
         return $this;
     }
 
-    public function fileToNotEqual($expected, string $message = ''): self
+    public function fileToNotEqual(string $expected, string $message = ''): self
     {
         Expect::File($this->actual)->toNotEqual($expected, $message);
         return $this;
     }
 
-    public function fileToNotEqualCanonicalizing($expected, string $message = ''): self
+    public function fileToNotEqualCanonicalizing(string $expected, string $message = ''): self
     {
         Expect::File($this->actual)->toNotEqualCanonicalizing($expected, $message);
         return $this;
     }
 
-    public function fileToNotEqualIgnoringCase($expected, string $message = ''): self
+    public function fileToNotEqualIgnoringCase(string $expected, string $message = ''): self
     {
         Expect::File($this->actual)->toNotEqualIgnoringCase($expected, $message);
         return $this;
     }
 
-    public function jsonFileToEqualJsonFile($expectedFile, string $message = ''): self
+    public function jsonFileToEqualJsonFile(string $expectedFile, string $message = ''): self
     {
         Expect::JsonFile($this->actual)->toEqualJsonFile($expectedFile, $message);
         return $this;
     }
 
-    public function jsonFileNotToEqualJsonFile($expectedFile, string $message = ''): self
+    public function jsonFileNotToEqualJsonFile(string $expectedFile, string $message = ''): self
     {
         Expect::JsonFile($this->actual)->notToEqualJsonFile($expectedFile, $message);
         return $this;
     }
 
-    public function jsonStringToEqualJsonFile($expectedFile, string $message = ''): self
+    public function jsonStringToEqualJsonFile(string $expectedFile, string $message = ''): self
     {
         Expect::JsonString($this->actual)->toEqualJsonFile($expectedFile, $message);
         return $this;
     }
 
-    public function jsonStringToEqualJsonString($expectedJson, string $message = ''): self
+    public function jsonStringToEqualJsonString(string $expectedJson, string $message = ''): self
     {
         Expect::JsonString($this->actual)->toEqualJsonString($expectedJson, $message);
         return $this;
     }
 
-    public function jsonStringNotToEqualJsonFile($expectedFile, string $message = ''): self
+    public function jsonStringNotToEqualJsonFile(string $expectedFile, string $message = ''): self
     {
         Expect::JsonString($this->actual)->notToEqualJsonFile($expectedFile, $message);
         return $this;
     }
 
-    public function jsonStringNotToEqualJsonString($expectedJson, string $message = ''): self
+    public function jsonStringNotToEqualJsonString(string $expectedJson, string $message = ''): self
     {
         Expect::JsonString($this->actual)->notToEqualJsonString($expectedJson, $message);
         return $this;
     }
 
-    public function stringToContainString($needle, string $message = ''): self
+    public function stringToContainString(string $needle, string $message = ''): self
     {
         Expect::String($this->actual)->toContainString($needle, $message);
         return $this;
@@ -288,31 +290,31 @@ public function stringToContainStringIgnoringCase($needle, string $message = '')
         return $this;
     }
 
-    public function stringNotToMatchRegExp($pattern, string $message = ''): self
+    public function stringNotToMatchRegExp(string $pattern, string $message = ''): self
     {
         Expect::String($this->actual)->notToMatchRegExp($pattern, $message);
         return $this;
     }
 
-    public function stringToEndWith($suffix, string $message = ''): self
+    public function stringToEndWith(string $suffix, string $message = ''): self
     {
         Expect::String($this->actual)->toEndWith($suffix, $message);
         return $this;
     }
 
-    public function stringToEqualFile($expectedFile, string $message = ''): self
+    public function stringToEqualFile(string $expectedFile, string $message = ''): self
     {
         Expect::String($this->actual)->toEqualFile($expectedFile, $message);
         return $this;
     }
 
-    public function stringToEqualFileCanonicalizing($expectedFile, string $message = ''): self
+    public function stringToEqualFileCanonicalizing(string $expectedFile, string $message = ''): self
     {
         Expect::String($this->actual)->toEqualFileCanonicalizing($expectedFile, $message);
         return $this;
     }
 
-    public function stringToEqualFileIgnoringCase($expectedFile, string $message = ''): self
+    public function stringToEqualFileIgnoringCase(string $expectedFile, string $message = ''): self
     {
         Expect::String($this->actual)->toEqualFileIgnoringCase($expectedFile, $message);
         return $this;
@@ -324,55 +326,55 @@ public function stringToBeJson(string $message = ''): self
         return $this;
     }
 
-    public function stringToMatchFormat($format, string $message = ''): self
+    public function stringToMatchFormat(string $format, string $message = ''): self
     {
         Expect::String($this->actual)->toMatchFormat($format, $message);
         return $this;
     }
 
-    public function stringToMatchFormatFile($formatFile, string $message = ''): self
+    public function stringToMatchFormatFile(string $formatFile, string $message = ''): self
     {
         Expect::String($this->actual)->toMatchFormatFile($formatFile, $message);
         return $this;
     }
 
-    public function stringToMatchRegExp($pattern, string $message = ''): self
+    public function stringToMatchRegExp(string $pattern, string $message = ''): self
     {
         Expect::String($this->actual)->toMatchRegExp($pattern, $message);
         return $this;
     }
 
-    public function stringNotToContainString($needle, string $message = ''): self
+    public function stringNotToContainString(string $needle, string $message = ''): self
     {
         Expect::String($this->actual)->notToContainString($needle, $message);
         return $this;
     }
 
-    public function stringNotToContainStringIgnoringCase($needle, string $message = ''): self
+    public function stringNotToContainStringIgnoringCase(string $needle, string $message = ''): self
     {
         Expect::String($this->actual)->notToContainStringIgnoringCase($needle, $message);
         return $this;
     }
 
-    public function stringNotToEndWith($suffix, string $message = ''): self
+    public function stringNotToEndWith(string $suffix, string $message = ''): self
     {
         Expect::String($this->actual)->notToEndWith($suffix, $message);
         return $this;
     }
 
-    public function stringNotToEqualFile($expectedFile, string $message = ''): self
+    public function stringNotToEqualFile(string $expectedFile, string $message = ''): self
     {
         Expect::String($this->actual)->notToEqualFile($expectedFile, $message);
         return $this;
     }
 
-    public function stringNotToEqualFileCanonicalizing($expectedFile, string $message = ''): self
+    public function stringNotToEqualFileCanonicalizing(string $expectedFile, string $message = ''): self
     {
         Expect::String($this->actual)->notToEqualFileCanonicalizing($expectedFile, $message);
         return $this;
     }
 
-    public function stringNotToEqualFileIgnoringCase($expectedFile, string $message = ''): self
+    public function stringNotToEqualFileIgnoringCase(string $expectedFile, string $message = ''): self
     {
         Expect::String($this->actual)->notToEqualFileIgnoringCase($expectedFile, $message);
         return $this;
@@ -384,37 +386,37 @@ public function stringNotToMatchFormat($format, string $message = ''): self
         return $this;
     }
 
-    public function stringNotToMatchFormatFile($formatFile, string $message = ''): self
+    public function stringNotToMatchFormatFile(string $formatFile, string $message = ''): self
     {
         Expect::String($this->actual)->notToMatchFormatFile($formatFile, $message);
         return $this;
     }
 
-    public function stringNotToStartWith($prefix, string $message = ''): self
+    public function stringNotToStartWith(string $prefix, string $message = ''): self
     {
         Expect::String($this->actual)->notToStartWith($prefix, $message);
         return $this;
     }
 
-    public function stringToStartWith($prefix, string $message = ''): self
+    public function stringToStartWith(string $prefix, string $message = ''): self
     {
         Expect::String($this->actual)->toStartWith($prefix, $message);
         return $this;
     }
 
-    public function xmlFileToEqualXmlFile($expectedFile, string $message = ''): self
+    public function xmlFileToEqualXmlFile(string $expectedFile, string $message = ''): self
     {
         Expect::XmlFile($this->actual)->toEqualXmlFile($expectedFile, $message);
         return $this;
     }
 
-    public function xmlFileNotToEqualXmlFile($expectedFile, string $message = ''): self
+    public function xmlFileNotToEqualXmlFile(string $expectedFile, string $message = ''): self
     {
         Expect::XmlFile($this->actual)->notToEqualXmlFile($expectedFile, $message);
         return $this;
     }
 
-    public function xmlStringToEqualXmlFile($expectedFile, string $message = ''): self
+    public function xmlStringToEqualXmlFile(string $expectedFile, string $message = ''): self
     {
         Expect::XmlString($this->actual)->toEqualXmlFile($expectedFile, $message);
         return $this;
@@ -426,7 +428,7 @@ public function xmlStringToEqualXmlString($expectedXml, string $message = ''): s
         return $this;
     }
 
-    public function xmlStringNotToEqualXmlFile($expectedFile, string $message = ''): self
+    public function xmlStringNotToEqualXmlFile(string $expectedFile, string $message = ''): self
     {
         Expect::XmlString($this->actual)->notToEqualXmlFile($expectedFile, $message);
         return $this;
diff --git a/src/Codeception/Verify/Expectations/ExpectArray.php b/src/Codeception/Verify/Expectations/ExpectArray.php
index f96511b..1be87ee 100644
--- a/src/Codeception/Verify/Expectations/ExpectArray.php
+++ b/src/Codeception/Verify/Expectations/ExpectArray.php
@@ -1,4 +1,6 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace Codeception\Verify\Expectations;
 
@@ -29,6 +31,7 @@ public function __construct($actual)
             parent::__construct($actual);
             return;
         }
+        
         throw new InvalidVerifyException(basename(self::class), $actual);
     }
 
@@ -45,7 +48,7 @@ public function notToContain($needle, string $message = ''): self
         return $this;
     }
 
-    public function notToContainEqual($needle, $message = ''): self
+    public function notToContainEqual($needle, string $message = ''): self
     {
         Assert::assertNotContainsEquals($needle, $this->actual, $message);
         return $this;
diff --git a/src/Codeception/Verify/Expectations/ExpectBaseObject.php b/src/Codeception/Verify/Expectations/ExpectBaseObject.php
index 520c7a0..394be23 100644
--- a/src/Codeception/Verify/Expectations/ExpectBaseObject.php
+++ b/src/Codeception/Verify/Expectations/ExpectBaseObject.php
@@ -1,4 +1,6 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace Codeception\Verify\Expectations;
 
diff --git a/src/Codeception/Verify/Expectations/ExpectCallable.php b/src/Codeception/Verify/Expectations/ExpectCallable.php
index 122852b..d4f177b 100644
--- a/src/Codeception/Verify/Expectations/ExpectCallable.php
+++ b/src/Codeception/Verify/Expectations/ExpectCallable.php
@@ -1,4 +1,6 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace Codeception\Verify\Expectations;
 
diff --git a/src/Codeception/Verify/Expectations/ExpectClass.php b/src/Codeception/Verify/Expectations/ExpectClass.php
index 30c5ee8..7077f7b 100644
--- a/src/Codeception/Verify/Expectations/ExpectClass.php
+++ b/src/Codeception/Verify/Expectations/ExpectClass.php
@@ -1,4 +1,6 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace Codeception\Verify\Expectations;
 
diff --git a/src/Codeception/Verify/Expectations/ExpectDataTrait.php b/src/Codeception/Verify/Expectations/ExpectDataTrait.php
index b352b5d..a3565b9 100644
--- a/src/Codeception/Verify/Expectations/ExpectDataTrait.php
+++ b/src/Codeception/Verify/Expectations/ExpectDataTrait.php
@@ -1,4 +1,6 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace Codeception\Verify\Expectations;
 
diff --git a/src/Codeception/Verify/Expectations/ExpectDirectory.php b/src/Codeception/Verify/Expectations/ExpectDirectory.php
index 6fee18a..5846792 100644
--- a/src/Codeception/Verify/Expectations/ExpectDirectory.php
+++ b/src/Codeception/Verify/Expectations/ExpectDirectory.php
@@ -1,4 +1,6 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace Codeception\Verify\Expectations;
 
diff --git a/src/Codeception/Verify/Expectations/ExpectFile.php b/src/Codeception/Verify/Expectations/ExpectFile.php
index d8a760f..9b4e8a4 100644
--- a/src/Codeception/Verify/Expectations/ExpectFile.php
+++ b/src/Codeception/Verify/Expectations/ExpectFile.php
@@ -1,4 +1,6 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace Codeception\Verify\Expectations;
 
diff --git a/src/Codeception/Verify/Expectations/ExpectJsonFile.php b/src/Codeception/Verify/Expectations/ExpectJsonFile.php
index 9a578d9..4fb0c43 100644
--- a/src/Codeception/Verify/Expectations/ExpectJsonFile.php
+++ b/src/Codeception/Verify/Expectations/ExpectJsonFile.php
@@ -1,4 +1,6 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace Codeception\Verify\Expectations;
 
diff --git a/src/Codeception/Verify/Expectations/ExpectJsonString.php b/src/Codeception/Verify/Expectations/ExpectJsonString.php
index 8ac7659..a6e61bc 100644
--- a/src/Codeception/Verify/Expectations/ExpectJsonString.php
+++ b/src/Codeception/Verify/Expectations/ExpectJsonString.php
@@ -1,4 +1,6 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace Codeception\Verify\Expectations;
 
diff --git a/src/Codeception/Verify/Expectations/ExpectMixed.php b/src/Codeception/Verify/Expectations/ExpectMixed.php
index 9e0a54a..6513c51 100644
--- a/src/Codeception/Verify/Expectations/ExpectMixed.php
+++ b/src/Codeception/Verify/Expectations/ExpectMixed.php
@@ -1,4 +1,6 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace Codeception\Verify\Expectations;
 
diff --git a/src/Codeception/Verify/Expectations/ExpectString.php b/src/Codeception/Verify/Expectations/ExpectString.php
index 5c32060..01e4624 100644
--- a/src/Codeception/Verify/Expectations/ExpectString.php
+++ b/src/Codeception/Verify/Expectations/ExpectString.php
@@ -1,4 +1,6 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace Codeception\Verify\Expectations;
 
@@ -83,7 +85,7 @@ public function notToEqualFileIgnoringCase(string $expectedFile, string $message
      * @param string $message
      * @return self
      */
-    public function notToMatchFormat($format, string $message = ''): self
+    public function notToMatchFormat(string $format, string $message = ''): self
     {
         Assert::assertStringNotMatchesFormat($format, $this->actual, $message);
         return $this;
@@ -146,7 +148,7 @@ public function toContainString(string $needle, string $message = ''): self
         return $this;
     }
 
-    public function toContainStringIgnoringCase($needle, string $message = ''): self
+    public function toContainStringIgnoringCase(string $needle, string $message = ''): self
     {
         Assert::assertStringContainsStringIgnoringCase($needle, $this->actual, $message);
         return $this;
diff --git a/src/Codeception/Verify/Expectations/ExpectXmlFile.php b/src/Codeception/Verify/Expectations/ExpectXmlFile.php
index 18dde3f..1a69207 100644
--- a/src/Codeception/Verify/Expectations/ExpectXmlFile.php
+++ b/src/Codeception/Verify/Expectations/ExpectXmlFile.php
@@ -1,4 +1,6 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace Codeception\Verify\Expectations;
 
diff --git a/src/Codeception/Verify/Expectations/ExpectXmlString.php b/src/Codeception/Verify/Expectations/ExpectXmlString.php
index 98bb18c..8a31ea5 100644
--- a/src/Codeception/Verify/Expectations/ExpectXmlString.php
+++ b/src/Codeception/Verify/Expectations/ExpectXmlString.php
@@ -1,4 +1,6 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace Codeception\Verify\Expectations;
 
@@ -22,6 +24,7 @@ public function __construct($actualXml)
             parent::__construct($actualXml);
             return;
         }
+        
         throw new InvalidVerifyException(basename(self::class), $actualXml);
     }
 
diff --git a/src/Codeception/Verify/Verifiers/VerifyAny.php b/src/Codeception/Verify/Verifiers/VerifyAny.php
index f372863..c1bcc15 100644
--- a/src/Codeception/Verify/Verifiers/VerifyAny.php
+++ b/src/Codeception/Verify/Verifiers/VerifyAny.php
@@ -1,4 +1,6 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace Codeception\Verify\Verifiers;
 
@@ -18,19 +20,19 @@ public function arrayContainsEquals($needle, string $message = ''): self
         return $this;
     }
 
-    public function arrayContainsOnly($type, $isNativeType = null, string $message = ''): self
+    public function arrayContainsOnly(string $type, ?bool $isNativeType = null, string $message = ''): self
     {
         Verify::Array($this->actual)->containsOnly($type, $isNativeType, $message);
         return $this;
     }
 
-    public function arrayContainsOnlyInstancesOf($className, string $message = ''): self
+    public function arrayContainsOnlyInstancesOf(string $className, string $message = ''): self
     {
         Verify::Array($this->actual)->containsOnlyInstancesOf($className, $message);
         return $this;
     }
 
-    public function arrayCount($expectedCount, string $message = ''): self
+    public function arrayCount(int $expectedCount, string $message = ''): self
     {
         Verify::Array($this->actual)->count($expectedCount, $message);
         return $this;
@@ -60,13 +62,13 @@ public function arrayNotContainsEquals($needle, string $message = ''): self
         return $this;
     }
 
-    public function arrayNotContainsOnly($type, $isNativeType = null, string $message = ''): self
+    public function arrayNotContainsOnly(string $type, ?bool $isNativeType = null, string $message = ''): self
     {
         Verify::Array($this->actual)->notContainsOnly($type, $isNativeType, $message);
         return $this;
     }
 
-    public function arrayNotCount($expectedCount, string $message = ''): self
+    public function arrayNotCount(int $expectedCount, string $message = ''): self
     {
         Verify::Array($this->actual)->notCount($expectedCount, $message);
         return $this;
@@ -84,13 +86,13 @@ public function arraySameSize($expected, string $message = ''): self
         return $this;
     }
 
-    public function baseObjectHasAttribute($attributeName, string $message = ''): self
+    public function baseObjectHasAttribute(string $attributeName, string $message = ''): self
     {
         Verify::BaseObject($this->actual)->hasAttribute($attributeName, $message);
         return $this;
     }
 
-    public function baseObjectNotHasAttribute($attributeName, string $message = ''): self
+    public function baseObjectNotHasAttribute(string $attributeName, string $message = ''): self
     {
         Verify::BaseObject($this->actual)->notHasAttribute($attributeName, $message);
         return $this;
@@ -108,25 +110,25 @@ public function callableDoesNotThrow($throws = null, string $message = ''): self
         return $this;
     }
 
-    public function classHasAttribute($attributeName, string $message = ''): self
+    public function classHasAttribute(string $attributeName, string $message = ''): self
     {
         Verify::Class($this->actual)->hasAttribute($attributeName, $message);
         return $this;
     }
 
-    public function classHasStaticAttribute($attributeName, string $message = ''): self
+    public function classHasStaticAttribute(string $attributeName, string $message = ''): self
     {
         Verify::Class($this->actual)->hasStaticAttribute($attributeName, $message);
         return $this;
     }
 
-    public function classNotHasAttribute($attributeName, string $message = ''): self
+    public function classNotHasAttribute(string $attributeName, string $message = ''): self
     {
         Verify::Class($this->actual)->notHasAttribute($attributeName, $message);
         return $this;
     }
 
-    public function classNotHasStaticAttribute($attributeName, string $message = ''): self
+    public function classNotHasStaticAttribute(string $attributeName, string $message = ''): self
     {
         Verify::Class($this->actual)->notHasStaticAttribute($attributeName, $message);
         return $this;
@@ -174,19 +176,19 @@ public function fileDoesNotExists(string $message = ''): self
         return $this;
     }
 
-    public function fileEquals($expected, string $message = ''): self
+    public function fileEquals(string $expected, string $message = ''): self
     {
         Verify::File($this->actual)->equals($expected, $message);
         return $this;
     }
 
-    public function fileEqualsCanonicalizing($expected, string $message = ''): self
+    public function fileEqualsCanonicalizing(string $expected, string $message = ''): self
     {
         Verify::File($this->actual)->equalsCanonicalizing($expected, $message);
         return $this;
     }
 
-    public function fileEqualsIgnoringCase($expected, string $message = ''): self
+    public function fileEqualsIgnoringCase(string $expected, string $message = ''): self
     {
         Verify::File($this->actual)->equalsIgnoringCase($expected, $message);
         return $this;
@@ -222,61 +224,61 @@ public function fileIsWritable(string $message = ''): self
         return $this;
     }
 
-    public function fileNotEquals($expected, string $message = ''): self
+    public function fileNotEquals(string $expected, string $message = ''): self
     {
         Verify::File($this->actual)->notEquals($expected, $message);
         return $this;
     }
 
-    public function fileNotEqualsCanonicalizing($expected, string $message = ''): self
+    public function fileNotEqualsCanonicalizing(string $expected, string $message = ''): self
     {
         Verify::File($this->actual)->notEqualsCanonicalizing($expected, $message);
         return $this;
     }
 
-    public function fileNotEqualsIgnoringCase($expected, string $message = ''): self
+    public function fileNotEqualsIgnoringCase(string $expected, string $message = ''): self
     {
         Verify::File($this->actual)->notEqualsIgnoringCase($expected, $message);
         return $this;
     }
 
-    public function jsonFileEqualsJsonFile($expectedFile, string $message = ''): self
+    public function jsonFileEqualsJsonFile(string $expectedFile, string $message = ''): self
     {
         Verify::JsonFile($this->actual)->equalsJsonFile($expectedFile, $message);
         return $this;
     }
 
-    public function jsonFileNotEqualsJsonFile($expectedFile, string $message = ''): self
+    public function jsonFileNotEqualsJsonFile(string $expectedFile, string $message = ''): self
     {
         Verify::JsonFile($this->actual)->notEqualsJsonFile($expectedFile, $message);
         return $this;
     }
 
-    public function jsonStringEqualsJsonFile($expectedFile, string $message = ''): self
+    public function jsonStringEqualsJsonFile(string $expectedFile, string $message = ''): self
     {
         Verify::JsonString($this->actual)->equalsJsonFile($expectedFile, $message);
         return $this;
     }
 
-    public function jsonStringEqualsJsonString($expectedJson, string $message = ''): self
+    public function jsonStringEqualsJsonString(string $expectedJson, string $message = ''): self
     {
         Verify::JsonString($this->actual)->equalsJsonString($expectedJson, $message);
         return $this;
     }
 
-    public function jsonStringNotEqualsJsonFile($expectedFile, string $message = ''): self
+    public function jsonStringNotEqualsJsonFile(string $expectedFile, string $message = ''): self
     {
         Verify::JsonString($this->actual)->notEqualsJsonFile($expectedFile, $message);
         return $this;
     }
 
-    public function jsonStringNotEqualsJsonString($expectedJson, string $message = ''): self
+    public function jsonStringNotEqualsJsonString(string $expectedJson, string $message = ''): self
     {
         Verify::JsonString($this->actual)->notEqualsJsonString($expectedJson, $message);
         return $this;
     }
 
-    public function stringContainsString($needle, string $message = ''): self
+    public function stringContainsString(string $needle, string $message = ''): self
     {
         Verify::String($this->actual)->containsString($needle, $message);
         return $this;
@@ -288,31 +290,31 @@ public function stringContainsStringIgnoringCase($needle, string $message = ''):
         return $this;
     }
 
-    public function stringDoesNotMatchRegExp($pattern, string $message = ''): self
+    public function stringDoesNotMatchRegExp(string $pattern, string $message = ''): self
     {
         Verify::String($this->actual)->doesNotMatchRegExp($pattern, $message);
         return $this;
     }
 
-    public function stringEndsWith($suffix, string $message = ''): self
+    public function stringEndsWith(string $suffix, string $message = ''): self
     {
         Verify::String($this->actual)->endsWith($suffix, $message);
         return $this;
     }
 
-    public function stringEqualsFile($expectedFile, string $message = ''): self
+    public function stringEqualsFile(string $expectedFile, string $message = ''): self
     {
         Verify::String($this->actual)->equalsFile($expectedFile, $message);
         return $this;
     }
 
-    public function stringEqualsFileCanonicalizing($expectedFile, string $message = ''): self
+    public function stringEqualsFileCanonicalizing(string $expectedFile, string $message = ''): self
     {
         Verify::String($this->actual)->equalsFileCanonicalizing($expectedFile, $message);
         return $this;
     }
 
-    public function stringEqualsFileIgnoringCase($expectedFile, string $message = ''): self
+    public function stringEqualsFileIgnoringCase(string $expectedFile, string $message = ''): self
     {
         Verify::String($this->actual)->equalsFileIgnoringCase($expectedFile, $message);
         return $this;
@@ -324,55 +326,55 @@ public function stringJson(string $message = ''): self
         return $this;
     }
 
-    public function stringMatchesFormat($format, string $message = ''): self
+    public function stringMatchesFormat(string $format, string $message = ''): self
     {
         Verify::String($this->actual)->matchesFormat($format, $message);
         return $this;
     }
 
-    public function stringMatchesFormatFile($formatFile, string $message = ''): self
+    public function stringMatchesFormatFile(string $formatFile, string $message = ''): self
     {
         Verify::String($this->actual)->matchesFormatFile($formatFile, $message);
         return $this;
     }
 
-    public function stringMatchesRegExp($pattern, string $message = ''): self
+    public function stringMatchesRegExp(string $pattern, string $message = ''): self
     {
         Verify::String($this->actual)->matchesRegExp($pattern, $message);
         return $this;
     }
 
-    public function stringNotContainsString($needle, string $message = ''): self
+    public function stringNotContainsString(string $needle, string $message = ''): self
     {
         Verify::String($this->actual)->notContainsString($needle, $message);
         return $this;
     }
 
-    public function stringNotContainsStringIgnoringCase($needle, string $message = ''): self
+    public function stringNotContainsStringIgnoringCase(string $needle, string $message = ''): self
     {
         Verify::String($this->actual)->notContainsStringIgnoringCase($needle, $message);
         return $this;
     }
 
-    public function stringNotEndsWith($suffix, string $message = ''): self
+    public function stringNotEndsWith(string $suffix, string $message = ''): self
     {
         Verify::String($this->actual)->notEndsWith($suffix, $message);
         return $this;
     }
 
-    public function stringNotEqualsFile($expectedFile, string $message = ''): self
+    public function stringNotEqualsFile(string $expectedFile, string $message = ''): self
     {
         Verify::String($this->actual)->notEqualsFile($expectedFile, $message);
         return $this;
     }
 
-    public function stringNotEqualsFileCanonicalizing($expectedFile, string $message = ''): self
+    public function stringNotEqualsFileCanonicalizing(string $expectedFile, string $message = ''): self
     {
         Verify::String($this->actual)->notEqualsFileCanonicalizing($expectedFile, $message);
         return $this;
     }
 
-    public function stringNotEqualsFileIgnoringCase($expectedFile, string $message = ''): self
+    public function stringNotEqualsFileIgnoringCase(string $expectedFile, string $message = ''): self
     {
         Verify::String($this->actual)->notEqualsFileIgnoringCase($expectedFile, $message);
         return $this;
@@ -384,37 +386,37 @@ public function stringNotMatchesFormat($format, string $message = ''): self
         return $this;
     }
 
-    public function stringNotMatchesFormatFile($formatFile, string $message = ''): self
+    public function stringNotMatchesFormatFile(string $formatFile, string $message = ''): self
     {
         Verify::String($this->actual)->notMatchesFormatFile($formatFile, $message);
         return $this;
     }
 
-    public function stringStartsNotWith($prefix, string $message = ''): self
+    public function stringStartsNotWith(string $prefix, string $message = ''): self
     {
         Verify::String($this->actual)->startsNotWith($prefix, $message);
         return $this;
     }
 
-    public function stringStartsWith($prefix, string $message = ''): self
+    public function stringStartsWith(string $prefix, string $message = ''): self
     {
         Verify::String($this->actual)->startsWith($prefix, $message);
         return $this;
     }
 
-    public function xmlFileEqualsXmlFile($expectedFile, string $message = ''): self
+    public function xmlFileEqualsXmlFile(string $expectedFile, string $message = ''): self
     {
         Verify::XmlFile($this->actual)->equalsXmlFile($expectedFile, $message);
         return $this;
     }
 
-    public function xmlFileNotEqualsXmlFile($expectedFile, string $message = ''): self
+    public function xmlFileNotEqualsXmlFile(string $expectedFile, string $message = ''): self
     {
         Verify::XmlFile($this->actual)->notEqualsXmlFile($expectedFile, $message);
         return $this;
     }
 
-    public function xmlStringEqualsXmlFile($expectedFile, string $message = ''): self
+    public function xmlStringEqualsXmlFile(string $expectedFile, string $message = ''): self
     {
         Verify::XmlString($this->actual)->equalsXmlFile($expectedFile, $message);
         return $this;
@@ -426,7 +428,7 @@ public function xmlStringEqualsXmlString($expectedXml, string $message = ''): se
         return $this;
     }
 
-    public function xmlStringNotEqualsXmlFile($expectedFile, string $message = ''): self
+    public function xmlStringNotEqualsXmlFile(string $expectedFile, string $message = ''): self
     {
         Verify::XmlString($this->actual)->notEqualsXmlFile($expectedFile, $message);
         return $this;
diff --git a/src/Codeception/Verify/Verifiers/VerifyArray.php b/src/Codeception/Verify/Verifiers/VerifyArray.php
index 245116d..d7bc49d 100644
--- a/src/Codeception/Verify/Verifiers/VerifyArray.php
+++ b/src/Codeception/Verify/Verifiers/VerifyArray.php
@@ -1,4 +1,6 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace Codeception\Verify\Verifiers;
 
@@ -29,6 +31,7 @@ public function __construct($actual)
             parent::__construct($actual);
             return;
         }
+        
         throw new InvalidVerifyException(basename(self::class), $actual);
     }
 
@@ -130,7 +133,7 @@ public function notContains($needle, string $message = ''): self
         return $this;
     }
 
-    public function notContainsEquals($needle, $message = ''): self
+    public function notContainsEquals($needle, string $message = ''): self
     {
         Assert::assertNotContainsEquals($needle, $this->actual, $message);
         return $this;
diff --git a/src/Codeception/Verify/Verifiers/VerifyBaseObject.php b/src/Codeception/Verify/Verifiers/VerifyBaseObject.php
index ea7e41b..c937dc3 100644
--- a/src/Codeception/Verify/Verifiers/VerifyBaseObject.php
+++ b/src/Codeception/Verify/Verifiers/VerifyBaseObject.php
@@ -1,4 +1,6 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace Codeception\Verify\Verifiers;
 
diff --git a/src/Codeception/Verify/Verifiers/VerifyCallable.php b/src/Codeception/Verify/Verifiers/VerifyCallable.php
index d454623..7e4ae7b 100644
--- a/src/Codeception/Verify/Verifiers/VerifyCallable.php
+++ b/src/Codeception/Verify/Verifiers/VerifyCallable.php
@@ -1,4 +1,6 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace Codeception\Verify\Verifiers;
 
diff --git a/src/Codeception/Verify/Verifiers/VerifyClass.php b/src/Codeception/Verify/Verifiers/VerifyClass.php
index 7e759f8..8697c0b 100644
--- a/src/Codeception/Verify/Verifiers/VerifyClass.php
+++ b/src/Codeception/Verify/Verifiers/VerifyClass.php
@@ -1,4 +1,6 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace Codeception\Verify\Verifiers;
 
diff --git a/src/Codeception/Verify/Verifiers/VerifyDataTrait.php b/src/Codeception/Verify/Verifiers/VerifyDataTrait.php
index 624f398..bd27ba5 100644
--- a/src/Codeception/Verify/Verifiers/VerifyDataTrait.php
+++ b/src/Codeception/Verify/Verifiers/VerifyDataTrait.php
@@ -1,4 +1,6 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace Codeception\Verify\Verifiers;
 
diff --git a/src/Codeception/Verify/Verifiers/VerifyDirectory.php b/src/Codeception/Verify/Verifiers/VerifyDirectory.php
index e63f7be..7160e24 100644
--- a/src/Codeception/Verify/Verifiers/VerifyDirectory.php
+++ b/src/Codeception/Verify/Verifiers/VerifyDirectory.php
@@ -1,4 +1,6 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace Codeception\Verify\Verifiers;
 
diff --git a/src/Codeception/Verify/Verifiers/VerifyFile.php b/src/Codeception/Verify/Verifiers/VerifyFile.php
index 6066b2f..82abb23 100644
--- a/src/Codeception/Verify/Verifiers/VerifyFile.php
+++ b/src/Codeception/Verify/Verifiers/VerifyFile.php
@@ -1,4 +1,6 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace Codeception\Verify\Verifiers;
 
diff --git a/src/Codeception/Verify/Verifiers/VerifyJsonFile.php b/src/Codeception/Verify/Verifiers/VerifyJsonFile.php
index 3fb515c..1683e44 100644
--- a/src/Codeception/Verify/Verifiers/VerifyJsonFile.php
+++ b/src/Codeception/Verify/Verifiers/VerifyJsonFile.php
@@ -1,4 +1,6 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace Codeception\Verify\Verifiers;
 
diff --git a/src/Codeception/Verify/Verifiers/VerifyJsonString.php b/src/Codeception/Verify/Verifiers/VerifyJsonString.php
index 936b376..8f637be 100644
--- a/src/Codeception/Verify/Verifiers/VerifyJsonString.php
+++ b/src/Codeception/Verify/Verifiers/VerifyJsonString.php
@@ -1,4 +1,6 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace Codeception\Verify\Verifiers;
 
diff --git a/src/Codeception/Verify/Verifiers/VerifyMixed.php b/src/Codeception/Verify/Verifiers/VerifyMixed.php
index e5f47a3..365c733 100644
--- a/src/Codeception/Verify/Verifiers/VerifyMixed.php
+++ b/src/Codeception/Verify/Verifiers/VerifyMixed.php
@@ -1,4 +1,6 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace Codeception\Verify\Verifiers;
 
diff --git a/src/Codeception/Verify/Verifiers/VerifyString.php b/src/Codeception/Verify/Verifiers/VerifyString.php
index 373a1b8..64948b0 100644
--- a/src/Codeception/Verify/Verifiers/VerifyString.php
+++ b/src/Codeception/Verify/Verifiers/VerifyString.php
@@ -1,4 +1,6 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace Codeception\Verify\Verifiers;
 
@@ -18,7 +20,7 @@ public function containsString(string $needle, string $message = ''): self
         return $this;
     }
 
-    public function containsStringIgnoringCase($needle, string $message = ''): self
+    public function containsStringIgnoringCase(string $needle, string $message = ''): self
     {
         Assert::assertStringContainsStringIgnoringCase($needle, $this->actual, $message);
         return $this;
@@ -211,7 +213,7 @@ public function notEqualsFileIgnoringCase(string $expectedFile, string $message
      * @param string $message
      * @return self
      */
-    public function notMatchesFormat($format, string $message = ''): self
+    public function notMatchesFormat(string $format, string $message = ''): self
     {
         Assert::assertStringNotMatchesFormat($format, $this->actual, $message);
         return $this;
diff --git a/src/Codeception/Verify/Verifiers/VerifyXmlFile.php b/src/Codeception/Verify/Verifiers/VerifyXmlFile.php
index 2201e73..faec156 100644
--- a/src/Codeception/Verify/Verifiers/VerifyXmlFile.php
+++ b/src/Codeception/Verify/Verifiers/VerifyXmlFile.php
@@ -1,4 +1,6 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace Codeception\Verify\Verifiers;
 
diff --git a/src/Codeception/Verify/Verifiers/VerifyXmlString.php b/src/Codeception/Verify/Verifiers/VerifyXmlString.php
index a87b72c..ba06747 100644
--- a/src/Codeception/Verify/Verifiers/VerifyXmlString.php
+++ b/src/Codeception/Verify/Verifiers/VerifyXmlString.php
@@ -1,4 +1,6 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace Codeception\Verify\Verifiers;
 
@@ -22,6 +24,7 @@ public function __construct($actualXml)
             parent::__construct($actualXml);
             return;
         }
+        
         throw new InvalidVerifyException(basename(self::class), $actualXml);
     }
 
diff --git a/src/Codeception/Verify/Verify.php b/src/Codeception/Verify/Verify.php
index ac1c6f3..983c339 100644
--- a/src/Codeception/Verify/Verify.php
+++ b/src/Codeception/Verify/Verify.php
@@ -1,4 +1,6 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 namespace Codeception\Verify;
 
diff --git a/src/Codeception/bootstrap.php b/src/Codeception/bootstrap.php
index f446e4a..26d0541 100644
--- a/src/Codeception/bootstrap.php
+++ b/src/Codeception/bootstrap.php
@@ -1,4 +1,6 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 use Codeception\Verify\Expectations\ExpectAny;
 use Codeception\Verify\Verifiers\VerifyAny;
diff --git a/tests/InheritanceTest.php b/tests/InheritanceTest.php
index 476b863..6dc19a7 100644
--- a/tests/InheritanceTest.php
+++ b/tests/InheritanceTest.php
@@ -1,4 +1,6 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 include_once __DIR__.'/../src/Codeception/bootstrap.php';
 
@@ -30,7 +32,7 @@ public function __construct($actual = null)
         parent::__construct($actual);
     }
 
-    public function success(string $message = '')
+    public function success(string $message = ''): void
     {
         Assert::assertTrue(true, $message);
     }
diff --git a/tests/VerifyTest.php b/tests/VerifyTest.php
index 68f4cf7..f5ac5a3 100644
--- a/tests/VerifyTest.php
+++ b/tests/VerifyTest.php
@@ -1,4 +1,6 @@
-<?php declare(strict_types=1);
+<?php
+
+declare(strict_types=1);
 
 include_once __DIR__.'/../src/Codeception/bootstrap.php';
 
@@ -7,8 +9,7 @@
 
 final class VerifyTest extends TestCase
 {
-    /** @var DOMDocument */
-    protected $xml;
+    protected DOMDocument $xml;
 
     protected function setUp(): void
     {
@@ -76,8 +77,8 @@ public function testArrayHasKey(): void
     public function testIsInstanceOf(): void
     {
         $testClass = new DateTime();
-        verify($testClass)->instanceOf('DateTime');
-        verify($testClass)->notInstanceOf('DateTimeZone');
+        verify($testClass)->instanceOf(DateTime::class);
+        verify($testClass)->notInstanceOf(DateTimeZone::class);
     }
 
     public function testHasAttribute(): void