diff --git a/tests/File/FileHelperTest.php b/tests/File/FileHelperTest.php
index f31671af..b7653765 100644
--- a/tests/File/FileHelperTest.php
+++ b/tests/File/FileHelperTest.php
@@ -9,6 +9,26 @@
 
 final class FileHelperTest extends TestCase
 {
+    /**
+     * @dataProvider detectEOLDataProvider
+     */
+    public function testDetectEOL(
+        string $content,
+        string $expected,
+    ): void {
+        static::assertSame($expected, FileHelper::detectEOL($content));
+    }
+
+    /**
+     * @return iterable<array-key, array{string, string}>
+     */
+    public static function detectEOLDataProvider(): iterable
+    {
+        yield ['foo', \PHP_EOL];
+        yield ["foo\n", "\n"];
+        yield ["foo\r\n", "\r\n"];
+    }
+
     /**
      * @dataProvider removeDotDataProvider
      */
diff --git a/tests/Ruleset/RulesetTest.php b/tests/Ruleset/RulesetTest.php
index a26cb3a0..4fee3c42 100644
--- a/tests/Ruleset/RulesetTest.php
+++ b/tests/Ruleset/RulesetTest.php
@@ -69,5 +69,8 @@ protected function process(int $tokenPosition, array $tokens): void
 
         $ruleset->allowNonFixableRules(false);
         static::assertCount(1, $ruleset->getRules());
+
+        $ruleset->allowNonFixableRules();
+        static::assertCount(2, $ruleset->getRules());
     }
 }