diff --git a/lib/Doctrine/Inflector/GenericLanguageInflectorFactory.php b/lib/Doctrine/Inflector/GenericLanguageInflectorFactory.php
index 166061d..b6a9325 100644
--- a/lib/Doctrine/Inflector/GenericLanguageInflectorFactory.php
+++ b/lib/Doctrine/Inflector/GenericLanguageInflectorFactory.php
@@ -4,9 +4,15 @@
 
 namespace Doctrine\Inflector;
 
+use Doctrine\Inflector\Rules\Patterns;
 use Doctrine\Inflector\Rules\Ruleset;
+use Doctrine\Inflector\Rules\Substitution;
+use Doctrine\Inflector\Rules\Substitutions;
+use Doctrine\Inflector\Rules\Transformations;
+use Doctrine\Inflector\Rules\Word;
 
 use function array_unshift;
+use function is_array;
 
 abstract class GenericLanguageInflectorFactory implements LanguageInflectorFactory
 {
@@ -60,6 +66,33 @@ final public function withPluralRules(?Ruleset $pluralRules, bool $reset = false
         return $this;
     }
 
+    final public function withIrregulars(?array $irregulars, bool $reset = false): LanguageInflectorFactory
+    {
+        if ($reset) {
+            $this->pluralRulesets   = [];
+            $this->singularRulesets = [];
+        }
+
+        if (is_array($irregulars)) {
+            $newIrregulars = [];
+            foreach ($irregulars as $irregular) {
+                $newIrregulars[] = new Substitution(new Word($irregular[0]), new Word($irregular[1]));
+            }
+
+            $transf   = new Transformations();
+            $patterns = new Patterns();
+            $substs   = new Substitutions(...$newIrregulars);
+
+            $plural   = new Ruleset($transf, $patterns, $substs);
+            $singular = new Ruleset($transf, $patterns, $substs->getFlippedSubstitutions());
+
+            array_unshift($this->pluralRulesets, $plural);
+            array_unshift($this->singularRulesets, $singular);
+        }
+
+        return $this;
+    }
+
     abstract protected function getSingularRuleset(): Ruleset;
 
     abstract protected function getPluralRuleset(): Ruleset;
diff --git a/lib/Doctrine/Inflector/LanguageInflectorFactory.php b/lib/Doctrine/Inflector/LanguageInflectorFactory.php
index a58f43c..6d9d924 100644
--- a/lib/Doctrine/Inflector/LanguageInflectorFactory.php
+++ b/lib/Doctrine/Inflector/LanguageInflectorFactory.php
@@ -26,6 +26,16 @@ public function withSingularRules(?Ruleset $singularRules, bool $reset = false):
      */
     public function withPluralRules(?Ruleset $pluralRules, bool $reset = false): self;
 
+    /**
+     * Applies custom rules for irregular words
+     *
+     * @param mixed[][] $irregulars Array of arrays of strings in the format [['singular', 'plural'], ...]
+     * @param bool      $reset      If true, will unset default inflections for all new rules
+     *
+     * @return $this
+     */
+    public function withIrregulars(?array $irregulars, bool $reset = false): self;
+
     /**
      * Builds the inflector instance with all applicable rules
      */
diff --git a/tests/Doctrine/Tests/Inflector/InflectorWithIrregularsTest.php b/tests/Doctrine/Tests/Inflector/InflectorWithIrregularsTest.php
new file mode 100644
index 0000000..da60476
--- /dev/null
+++ b/tests/Doctrine/Tests/Inflector/InflectorWithIrregularsTest.php
@@ -0,0 +1,69 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Doctrine\Tests\Inflector;
+
+use Doctrine\Inflector\Inflector;
+use Doctrine\Inflector\InflectorFactory;
+use PHPUnit\Framework\TestCase;
+
+class InflectorWithIrregularsTest extends TestCase
+{
+    /** @var Inflector */
+    private $inflector;
+
+    /**
+     * @dataProvider dataIrregulars
+     */
+    public function testIrregulars(string $word, string $expected): void
+    {
+        self::assertSame($expected, $this->inflector->pluralize($word));
+        self::assertSame($word, $this->inflector->singularize($expected));
+    }
+
+    /**
+     * @dataProvider dataRegulars
+     */
+    public function testRegulars(string $word, string $expected): void
+    {
+        self::assertSame($expected, $this->inflector->pluralize($word));
+        self::assertSame($word, $this->inflector->singularize($expected));
+    }
+
+    /**
+     * Strings which are used for testTableize.
+     *
+     * @return string[][]
+     */
+    public function dataRegulars(): array
+    {
+        // In the format array('word', 'expected')
+        return [
+            ['address', 'addresses'],
+            ['advice', 'advice'],
+            ['agency', 'agencies'],
+            ['aircraft', 'aircraft'],
+            ['alias', 'aliases'],
+        ];
+    }
+
+    /**
+     * Strings which are used for testIrregulars.
+     *
+     * @return string[][]
+     */
+    public function dataIrregulars(): array
+    {
+        // In the format array('word', 'expected')
+        return [
+            ['foobar', 'barfoo'],
+            ['test', 'testz'],
+        ];
+    }
+
+    protected function setUp(): void
+    {
+        $this->inflector = InflectorFactory::create()->withIrregulars($this->dataIrregulars())->build();
+    }
+}