diff --git a/src/Ruleset/Ruleset.php b/src/Ruleset/Ruleset.php
index dc1be327..d825626e 100644
--- a/src/Ruleset/Ruleset.php
+++ b/src/Ruleset/Ruleset.php
@@ -4,6 +4,7 @@
 
 namespace TwigCsFixer\Ruleset;
 
+use TwigCsFixer\Rules\ConfigurableRuleInterface;
 use TwigCsFixer\Rules\FixableRuleInterface;
 use TwigCsFixer\Rules\RuleInterface;
 use TwigCsFixer\Standard\StandardInterface;
@@ -14,7 +15,7 @@
 final class Ruleset
 {
     /**
-     * @var array<RuleInterface>
+     * @var array<string, RuleInterface>
      */
     private array $rules = [];
 
@@ -28,18 +29,18 @@ public function allowNonFixableRules(bool $allowNonFixableRules = true): self
     }
 
     /**
-     * @return array<RuleInterface>
+     * @return list<RuleInterface>
      */
     public function getRules(): array
     {
         if (!$this->allowNonFixableRules) {
-            return array_filter(
+            return array_values(array_filter(
                 $this->rules,
                 static fn (RuleInterface $rule): bool => $rule instanceof FixableRuleInterface,
-            );
+            ));
         }
 
-        return $this->rules;
+        return array_values($this->rules);
     }
 
     /**
@@ -47,7 +48,12 @@ public function getRules(): array
      */
     public function addRule(RuleInterface $rule): self
     {
-        $this->rules[] = $rule;
+        $config = $rule instanceof ConfigurableRuleInterface
+            ? $rule->getConfiguration()
+            : null;
+        $key = $rule::class.md5(serialize($config));
+
+        $this->rules[$key] = $rule;
 
         return $this;
     }
diff --git a/src/Standard/StandardInterface.php b/src/Standard/StandardInterface.php
index cc4c41f7..98d2e591 100644
--- a/src/Standard/StandardInterface.php
+++ b/src/Standard/StandardInterface.php
@@ -9,7 +9,7 @@
 interface StandardInterface
 {
     /**
-     * @return RuleInterface[]
+     * @return list<RuleInterface>
      */
     public function getRules(): array;
 }
diff --git a/tests/Config/ConfigTest.php b/tests/Config/ConfigTest.php
index ad4d2fa0..21b7d90d 100644
--- a/tests/Config/ConfigTest.php
+++ b/tests/Config/ConfigTest.php
@@ -31,8 +31,8 @@ public function testConfigRuleset(): void
 
         $ruleset = $config->getRuleset();
         static::assertEquals(
-            array_values($genericStandard->getRules()),
-            array_values($ruleset->getRules())
+            $genericStandard->getRules(),
+            $ruleset->getRules()
         );
 
         $ruleset = new Ruleset();
diff --git a/tests/Ruleset/RulesetTest.php b/tests/Ruleset/RulesetTest.php
index fc7b573b..93a16a70 100644
--- a/tests/Ruleset/RulesetTest.php
+++ b/tests/Ruleset/RulesetTest.php
@@ -7,9 +7,7 @@
 use PHPUnit\Framework\TestCase;
 use TwigCsFixer\Rules\AbstractFixableRule;
 use TwigCsFixer\Rules\AbstractRule;
-use TwigCsFixer\Rules\RuleInterface;
-use TwigCsFixer\Rules\Whitespace\BlankEOFRule;
-use TwigCsFixer\Rules\Whitespace\TrailingSpaceRule;
+use TwigCsFixer\Rules\String\SingleQuoteRule;
 use TwigCsFixer\Ruleset\Ruleset;
 use TwigCsFixer\Standard\StandardInterface;
 
@@ -24,33 +22,26 @@ public function testStartWithNoRule(): void
     public function testAddAndRemoveRule(): void
     {
         $ruleset = new Ruleset();
-        $rule = self::createStub(RuleInterface::class);
+        $rule1 = new SingleQuoteRule(true);
+        $rule2 = new SingleQuoteRule(false);
 
-        $ruleset->addRule($rule);
+        $ruleset->addRule($rule1);
         static::assertCount(1, $ruleset->getRules());
 
-        $ruleset->addRule($rule);
-        static::assertCount(2, $ruleset->getRules());
-
-        $ruleset->overrideRule($rule);
+        $ruleset->addRule($rule1);
         static::assertCount(1, $ruleset->getRules());
 
-        $ruleset->removeRule($rule::class);
-        static::assertCount(0, $ruleset->getRules());
-    }
+        $ruleset->addRule($rule2);
+        static::assertCount(2, $ruleset->getRules());
 
-    public function testAddStandard(): void
-    {
-        $ruleset = new Ruleset();
+        $ruleset->removeRule(SingleQuoteRule::class);
+        static::assertCount(0, $ruleset->getRules());
 
-        // Using real rule to have different class name
-        $rule1 = new BlankEOFRule();
-        $rule2 = new TrailingSpaceRule();
-        $standard = self::createStub(StandardInterface::class);
-        $standard->method('getRules')->willReturn([$rule1, $rule2]);
+        $ruleset->addRule($rule1);
+        static::assertCount(1, $ruleset->getRules());
 
-        $ruleset->addStandard($standard);
-        static::assertCount(2, $ruleset->getRules());
+        $ruleset->overrideRule($rule2);
+        static::assertCount(1, $ruleset->getRules());
     }
 
     public function testAllowNonFixableRules(): void