diff --git a/src/Symfony/Component/Uid/Tests/UuidTest.php b/src/Symfony/Component/Uid/Tests/UuidTest.php
index fb431e0089..e43275230e 100644
--- a/src/Symfony/Component/Uid/Tests/UuidTest.php
+++ b/src/Symfony/Component/Uid/Tests/UuidTest.php
@@ -94,6 +94,22 @@ class UuidTest extends TestCase
         $this->assertFalse($uuid1->equals($uuid2));
     }
 
+    /**
+     * @dataProvider provideInvalidEqualType
+     */
+    public function testEqualsAgainstOtherType($other)
+    {
+        $this->assertFalse((new Uuid(self::A_UUID_V4))->equals($other));
+    }
+
+    public function provideInvalidEqualType()
+    {
+        yield [null];
+        yield [self::A_UUID_V1];
+        yield [self::A_UUID_V4];
+        yield [new \stdClass()];
+    }
+
     public function testCompare()
     {
         $uuids = [];
diff --git a/src/Symfony/Component/Uid/Uuid.php b/src/Symfony/Component/Uid/Uuid.php
index a6dd3536f3..1da54e7190 100644
--- a/src/Symfony/Component/Uid/Uuid.php
+++ b/src/Symfony/Component/Uid/Uuid.php
@@ -48,7 +48,7 @@ class Uuid implements \JsonSerializable
             throw new \InvalidArgumentException(sprintf('Invalid UUID: "%s".', $uuid));
         }
 
-        $this->uuid = $uuid;
+        $this->uuid = strtr($uuid, 'ABCDEF', 'abcdef');
     }
 
     public static function v1(): self
@@ -91,8 +91,15 @@ class Uuid implements \JsonSerializable
         return uuid_is_null($this->uuid);
     }
 
-    public function equals(self $other): bool
+    /**
+     * Returns whether the argument is of class Uuid and contains the same value as the current instance.
+     */
+    public function equals($other): bool
     {
+        if (!$other instanceof self) {
+            return false;
+        }
+
         return 0 === uuid_compare($this->uuid, $other->uuid);
     }