diff --git a/CHANGELOG.md b/CHANGELOG.md
index 611d627..557f51e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -25,6 +25,22 @@ Common and useful classes, methods, exceptions etc.
    }
    ```
 
+5. Change of `Meritoo\Common\Utilities\Regex::arrayFilter()` method signature:
+   1. 3rd argument, the filter, is now a `\Closure|string`. Previously it was `string`.
+   2. 4th argument has been removed (not necessary).
+
+   Before:
+
+   ```php
+   public static function arrayFilter(array $array, string $arrayColumnKey, string $filterExpression, bool $itsRegularExpression = false): array
+   ```
+
+   After:
+
+   ```php
+   public static function arrayFilter(array $array, string $arrayColumnKey, \Closure|string $filter): array
+   ```
+
 # 1.2.2
 
 1. Refactor the `Reflection` class for PHP `8.0`+
diff --git a/TODO.md b/TODO.md
index f67d794..7e39901 100644
--- a/TODO.md
+++ b/TODO.md
@@ -4,7 +4,7 @@
 
 ### Fix PHPStan errors
 
-- [ ] `Undefined variable: $isEqual` - replace `eval()` with callable
+- [x] `Undefined variable: $isEqual` - replace `eval()` with callable
   in [src/Utilities/Regex.php:151](./src/Utilities/Regex.php)
 - [x] `Unsafe usage of new static()` - chose one
   of [possible solutions](https://phpstan.org/blog/solving-phpstan-error-unsafe-usage-of-new-static) -
@@ -12,7 +12,7 @@
 - [x] `Unsafe usage of new static()` - chose one
   of [possible solutions](https://phpstan.org/blog/solving-phpstan-error-unsafe-usage-of-new-static) -
   in [src/Exception/Base/UnknownTypeException.php:40](./src/Exception/Base/UnknownTypeException.php)
-- [ ] Clean and remove the [phpstan-baseline.neon](phpstan-baseline.neon) file finally
+- [x] Clean and remove the [phpstan-baseline.neon](phpstan-baseline.neon) file finally
 
 ### Refactoring
 
diff --git a/phpstan.neon b/phpstan.neon
index 30b1537..31f6166 100644
--- a/phpstan.neon
+++ b/phpstan.neon
@@ -1,6 +1,3 @@
-includes:
-    - phpstan-baseline.neon
-
 parameters:
     level: 1
     paths:
diff --git a/src/Utilities/Regex.php b/src/Utilities/Regex.php
index ef8777a..2f4499b 100644
--- a/src/Utilities/Regex.php
+++ b/src/Utilities/Regex.php
@@ -102,19 +102,15 @@ public static function areValidHtmlAttributes(string $htmlAttributes): bool
      * Expression can be simple compare expression, like " == 2", or regular expression.
      * Returns filtered array.
      *
-     * @param array  $array                The 2-dimensional array that should be filtered
-     * @param string $arrayColumnKey       Column name
-     * @param string $filterExpression     Simple filter expression (e.g. "== 2" or "!= \'home\'") or regular
-     *                                     expression (e.g. "/\d+/" or "/[a-z]+[,;]{2,}/")
-     * @param bool   $itsRegularExpression (optional) If is set to true, means that filter expression is a regular
-     *                                     expression. Otherwise - not (default behaviour).
+     * @param array $array The 2-dimensional array that should be filtered
+     * @param string $arrayColumnKey Column name which value is verified by the filter
+     * @param \Closure|string $filter A filter that might be regular expression (string) or anonymous function (closure)
      * @return array
      */
     public static function arrayFilter(
         array $array,
         string $arrayColumnKey,
-        string $filterExpression,
-        bool $itsRegularExpression = false
+        \Closure|string $filter,
     ): array {
         /*
          * No elements?
@@ -132,25 +128,13 @@ public static function arrayFilter(
             }
 
             $value = $item[$arrayColumnKey];
+            $itsRegularExpression = \is_string($filter);
 
             if ($itsRegularExpression) {
-                $matchesCount = preg_match($filterExpression, $value);
+                $matchesCount = preg_match($filter, $value);
                 $remove = 0 === $matchesCount;
             } else {
-                if (is_string($value)) {
-                    $value = sprintf('\'%s\'', $value);
-                } elseif (is_bool($value)) {
-                    if (true === $value) {
-                        $value = 'true';
-                    } else {
-                        $value = 'false';
-                    }
-                }
-
-                eval(sprintf('$isEqual = %s%s;', $value, $filterExpression));
-
-                /** @var bool $isEqual */
-                $remove = !$isEqual;
+                $remove = !$filter($value);
             }
 
             if ($remove) {
diff --git a/tests/Utilities/RegexTest.php b/tests/Utilities/RegexTest.php
index d656b35..648bc2a 100644
--- a/tests/Utilities/RegexTest.php
+++ b/tests/Utilities/RegexTest.php
@@ -8,7 +8,6 @@
 
 namespace Meritoo\Test\Common\Utilities;
 
-use Generator;
 use Meritoo\Common\Exception\Regex\IncorrectColorHexLengthException;
 use Meritoo\Common\Exception\Regex\InvalidColorHexValueException;
 use Meritoo\Common\Test\Base\BaseTestCase;
@@ -32,9 +31,9 @@ class RegexTest extends BaseTestCase
     /**
      * Provides value to verify if it is a binary value
      *
-     * @return Generator
+     * @return \Generator
      */
-    public function provideBinaryValue()
+    public function provideBinaryValue(): \Generator
     {
         $file1Path = $this->getFilePathForTesting('lorem-ipsum.txt');
         $file2Path = $this->getFilePathForTesting('minion.jpg');
@@ -78,9 +77,9 @@ public function provideBinaryValue()
     /**
      * Provides name of bundle and information if it's valid name
      *
-     * @return Generator
+     * @return \Generator
      */
-    public function provideBundleName()
+    public function provideBundleName(): \Generator
     {
         yield [
             'something',
@@ -121,9 +120,9 @@ public function provideBundleName()
     /**
      * Provides value of color
      *
-     * @return Generator
+     * @return \Generator
      */
-    public function provideColor()
+    public function provideColor(): \Generator
     {
         yield [
             '#1b0',
@@ -154,9 +153,9 @@ public function provideColor()
     /**
      * Provides empty non color-related value
      *
-     * @return Generator
+     * @return \Generator
      */
-    public function provideColorEmptyValue()
+    public function provideColorEmptyValue(): \Generator
     {
         yield [
             '',
@@ -178,9 +177,9 @@ public function provideColorEmptyValue()
     /**
      * Provides value of color with incorrect length
      *
-     * @return Generator
+     * @return \Generator
      */
-    public function provideColorIncorrectLength()
+    public function provideColorIncorrectLength(): \Generator
     {
         yield [
             '12',
@@ -210,9 +209,9 @@ public function provideColorIncorrectLength()
     /**
      * Provides invalid value of color
      *
-     * @return Generator
+     * @return \Generator
      */
-    public function provideColorInvalidValue()
+    public function provideColorInvalidValue(): \Generator
     {
         yield [
             '#qwerty',
@@ -226,9 +225,9 @@ public function provideColorInvalidValue()
     /**
      * Provides e-mail and information if it's valid
      *
-     * @return Generator
+     * @return \Generator
      */
-    public function provideEmail()
+    public function provideEmail(): \Generator
     {
         yield [
             '1',
@@ -264,9 +263,9 @@ public function provideEmail()
     /**
      * Provides empty non money-related value
      *
-     * @return Generator
+     * @return \Generator
      */
-    public function provideEmptyNonMoneyValue()
+    public function provideEmptyNonMoneyValue(): \Generator
     {
         yield [''];
         yield ['   '];
@@ -275,7 +274,7 @@ public function provideEmptyNonMoneyValue()
         yield [[]];
     }
 
-    public function provideFileName(): ?Generator
+    public function provideFileName(): \Generator
     {
         yield [
             'An empty string',
@@ -311,9 +310,9 @@ public function provideFileName(): ?Generator
     /**
      * Provides html attribute and information if it's valid
      *
-     * @return Generator
+     * @return \Generator
      */
-    public function provideHtmlAttribute()
+    public function provideHtmlAttribute(): \Generator
     {
         yield [
             'abc = def',
@@ -349,9 +348,9 @@ public function provideHtmlAttribute()
     /**
      * Provides html attribute and information if attributes are valid
      *
-     * @return Generator
+     * @return \Generator
      */
-    public function provideHtmlAttributes()
+    public function provideHtmlAttributes(): \Generator
     {
         yield [
             'abc = def',
@@ -397,9 +396,9 @@ public function provideHtmlAttributes()
     /**
      * Provides money-related value and information if the value is valid
      *
-     * @return Generator
+     * @return \Generator
      */
-    public function provideMoneyValue()
+    public function provideMoneyValue(): \Generator
     {
         yield [
             'abc',
@@ -495,9 +494,9 @@ public function provideMoneyValue()
     /**
      * Provides pattern and array with keys that should match that pattern
      *
-     * @return Generator
+     * @return \Generator
      */
-    public function providePatternForArrayKeys()
+    public function providePatternForArrayKeys(): \Generator
     {
         yield [
             '/\d/',
@@ -537,9 +536,9 @@ public function providePatternForArrayKeys()
     /**
      * Provides pattern and array with values that should match that pattern
      *
-     * @return Generator
+     * @return \Generator
      */
-    public function providePatternForArrayValues()
+    public function providePatternForArrayValues(): \Generator
     {
         yield [
             '/\d/',
@@ -580,9 +579,9 @@ public function providePatternForArrayValues()
     /**
      * Provides patterns and subject for the pregMultiMatch() method
      *
-     * @return Generator
+     * @return \Generator
      */
-    public function providePatternsAndSubjectForPregMultiMatch()
+    public function providePatternsAndSubjectForPregMultiMatch(): \Generator
     {
         yield [
             '',
@@ -630,9 +629,9 @@ public function providePatternsAndSubjectForPregMultiMatch()
     /**
      * Provides patterns and subject for the pregMultiMatch() method when must match all patterns
      *
-     * @return Generator
+     * @return \Generator
      */
-    public function providePatternsAndSubjectForPregMultiMatchWhenMustMatchAllPatterns()
+    public function providePatternsAndSubjectForPregMultiMatchWhenMustMatchAllPatterns(): \Generator
     {
         yield [
             '',
@@ -680,9 +679,9 @@ public function providePatternsAndSubjectForPregMultiMatchWhenMustMatchAllPatter
     /**
      * Provides phone number and information if it's valid
      *
-     * @return Generator
+     * @return \Generator
      */
-    public function providePhoneNumber()
+    public function providePhoneNumber(): \Generator
     {
         yield [
             'abc',
@@ -711,11 +710,11 @@ public function providePhoneNumber()
     }
 
     /**
-     * Provides regular expression for array filtering and the array
+     * Provides regular expression for array filtering
      *
-     * @return Generator
+     * @return \Generator
      */
-    public function provideRegularExpressionForArrayFiltering()
+    public function provideRegularExpressionForArrayFiltering(): \Generator
     {
         yield [
             [],
@@ -876,20 +875,20 @@ public function provideRegularExpressionForArrayFiltering()
     }
 
     /**
-     * Provides simple compare expression for array filtering and the array
+     * Provides Closure for array filtering
      *
-     * @return Generator
+     * @return \Generator
      */
-    public function provideSimpleExpressionForArrayFiltering()
+    public function provideClosureForArrayFiltering(): \Generator
     {
-        yield [
+        yield 'an empty array' => [
             [],
             'id',
-            ' == 2',
+            fn($value) => $value == 2,
             [],
         ];
 
-        yield [
+        yield 'not existing column' => [
             [
                 [
                     'id' => 1,
@@ -911,7 +910,7 @@ public function provideSimpleExpressionForArrayFiltering()
                 ],
             ],
             'birth_date',
-            ' == 2',
+            fn($value) => $value == 2,
             [
                 [
                     'id' => 1,
@@ -934,7 +933,7 @@ public function provideSimpleExpressionForArrayFiltering()
             ],
         ];
 
-        yield [
+        yield 'non-strict equals 2' => [
             [
                 [
                     'id' => 1,
@@ -943,7 +942,7 @@ public function provideSimpleExpressionForArrayFiltering()
                     'is_active' => true,
                 ],
                 [
-                    'id' => 2,
+                    'id' => '2',
                     'first_name' => 'George',
                     'last_name' => 'Brown',
                     'is_active' => true,
@@ -954,20 +953,71 @@ public function provideSimpleExpressionForArrayFiltering()
                     'last_name' => 'Green',
                     'is_active' => false,
                 ],
+                [
+                    'id' => 2,
+                    'first_name' => 'Kate',
+                    'last_name' => 'Ryan',
+                    'is_active' => false,
+                ],
             ],
             'id',
-            ' == 2',
+            fn($value) => $value == 2,
             [
                 1 => [
+                    'id' => '2',
+                    'first_name' => 'George',
+                    'last_name' => 'Brown',
+                    'is_active' => true,
+                ],
+                3 => [
                     'id' => 2,
+                    'first_name' => 'Kate',
+                    'last_name' => 'Ryan',
+                    'is_active' => false,
+                ],
+            ],
+        ];
+
+        yield 'strict equals 2' => [
+            [
+                [
+                    'id' => 1,
+                    'first_name' => 'Jane',
+                    'last_name' => 'Scott',
+                    'is_active' => true,
+                ],
+                [
+                    'id' => '2',
                     'first_name' => 'George',
                     'last_name' => 'Brown',
                     'is_active' => true,
                 ],
+                [
+                    'id' => 3,
+                    'first_name' => 'Mike',
+                    'last_name' => 'Green',
+                    'is_active' => false,
+                ],
+                [
+                    'id' => 2,
+                    'first_name' => 'Kate',
+                    'last_name' => 'Ryan',
+                    'is_active' => false,
+                ],
+            ],
+            'id',
+            fn($value) => $value === 2,
+            [
+                3 => [
+                    'id' => 2,
+                    'first_name' => 'Kate',
+                    'last_name' => 'Ryan',
+                    'is_active' => false,
+                ],
             ],
         ];
 
-        yield [
+        yield 'greater than or equals 2' => [
             [
                 [
                     'id' => 1,
@@ -989,7 +1039,7 @@ public function provideSimpleExpressionForArrayFiltering()
                 ],
             ],
             'id',
-            ' >= 2',
+            fn($value) => $value >= 2,
             [
                 1 => [
                     'id' => 2,
@@ -1006,7 +1056,7 @@ public function provideSimpleExpressionForArrayFiltering()
             ],
         ];
 
-        yield [
+        yield 'strict not equals `true`' => [
             [
                 [
                     'id' => 1,
@@ -1028,7 +1078,7 @@ public function provideSimpleExpressionForArrayFiltering()
                 ],
             ],
             'is_active',
-            ' !== true',
+            fn($value) => $value !== true,
             [
                 2 => [
                     'id' => 3,
@@ -1039,7 +1089,40 @@ public function provideSimpleExpressionForArrayFiltering()
             ],
         ];
 
-        yield [
+        yield 'not `true`' => [
+            [
+                [
+                    'id' => 1,
+                    'first_name' => 'Jane',
+                    'last_name' => 'Scott',
+                    'is_active' => true,
+                ],
+                [
+                    'id' => 2,
+                    'first_name' => 'George',
+                    'last_name' => 'Brown',
+                    'is_active' => true,
+                ],
+                [
+                    'id' => 3,
+                    'first_name' => 'Mike',
+                    'last_name' => 'Green',
+                    'is_active' => false,
+                ],
+            ],
+            'is_active',
+            fn($value) => !$value,
+            [
+                2 => [
+                    'id' => 3,
+                    'first_name' => 'Mike',
+                    'last_name' => 'Green',
+                    'is_active' => false,
+                ],
+            ],
+        ];
+
+        yield 'equals `Mike`' => [
             [
                 [
                     'id' => 1,
@@ -1061,7 +1144,7 @@ public function provideSimpleExpressionForArrayFiltering()
                 ],
             ],
             'first_name',
-            ' == \'Mike\'',
+            fn($value) => $value === 'Mike',
             [
                 2 => [
                     'id' => 3,
@@ -1258,7 +1341,7 @@ public function provideSizeToVerify()
         ];
     }
 
-    public function provideStringToClearBeginningSlash(): ?Generator
+    public function provideStringToClearBeginningSlash(): \Generator
     {
         yield [
             '',
@@ -1361,7 +1444,7 @@ public function provideStringToClearBeginningSlash(): ?Generator
         ];
     }
 
-    public function provideStringToClearEndingSlash(): ?Generator
+    public function provideStringToClearEndingSlash(): \Generator
     {
         yield [
             '',
@@ -1467,9 +1550,9 @@ public function provideStringToClearEndingSlash(): ?Generator
     /**
      * Provides tax ID and information if it's valid
      *
-     * @return Generator
+     * @return \Generator
      */
-    public function provideTaxId()
+    public function provideTaxId(): \Generator
     {
         yield [
             '123',
@@ -1512,9 +1595,9 @@ public function provideTaxId()
     /**
      * Provide value to create slug
      *
-     * @return Generator
+     * @return \Generator
      */
-    public function provideValueSlug()
+    public function provideValueSlug(): \Generator
     {
         yield [
             '',
@@ -1602,30 +1685,24 @@ public static function testAreValidHtmlAttributesUsingEmptyValue($emptyValue)
         self::assertFalse(Regex::areValidHtmlAttributes($emptyValue));
     }
 
-    /**
-     * @param array  $array            The array that should be filtered
-     * @param string $arrayColumnKey   Column name
-     * @param string $filterExpression Regular expression, e.g. "/\d+/" or "/[a-z]+[,;]{2,}/"
-     * @param array  $expected         Expected array
-     *
-     * @dataProvider provideRegularExpressionForArrayFiltering
-     */
-    public function testArrayFilterUsingRegularExpression($array, $arrayColumnKey, $filterExpression, $expected)
-    {
-        self::assertEquals($expected, Regex::arrayFilter($array, $arrayColumnKey, $filterExpression, true));
+    /** @dataProvider provideRegularExpressionForArrayFiltering */
+    public function testArrayFilterUsingRegularExpression(
+        array $array,
+        string $arrayColumnKey,
+        string $filterExpression,
+        array $expected,
+    ): void {
+        self::assertEquals($expected, Regex::arrayFilter($array, $arrayColumnKey, $filterExpression));
     }
 
-    /**
-     * @param array  $array            The array that should be filtered
-     * @param string $arrayColumnKey   Column name
-     * @param string $filterExpression Simple filter expression, e.g. "== 2" or "!= \'home\'"
-     * @param array  $expected         Expected array
-     *
-     * @dataProvider provideSimpleExpressionForArrayFiltering
-     */
-    public function testArrayFilterUsingSimpleExpression($array, $arrayColumnKey, $filterExpression, $expected)
-    {
-        self::assertEquals($expected, Regex::arrayFilter($array, $arrayColumnKey, $filterExpression));
+    /** @dataProvider provideClosureForArrayFiltering */
+    public function testArrayFilterUsingSimpleExpression(
+        array $array,
+        string $arrayColumnKey,
+        \Closure $filter,
+        array $expected,
+    ): void {
+        self::assertEquals($expected, Regex::arrayFilter($array, $arrayColumnKey, $filter));
     }
 
     public function testCamelCase2humanReadable()