diff --git a/module/Core/src/Model/ShortUrlIdentifier.php b/module/Core/src/Model/ShortUrlIdentifier.php
index 4a74ba07..a277782c 100644
--- a/module/Core/src/Model/ShortUrlIdentifier.php
+++ b/module/Core/src/Model/ShortUrlIdentifier.php
@@ -5,6 +5,7 @@ declare(strict_types=1);
 namespace Shlinkio\Shlink\Core\Model;
 
 use Psr\Http\Message\ServerRequestInterface;
+use Shlinkio\Shlink\Core\Entity\ShortUrl;
 use Symfony\Component\Console\Input\InputInterface;
 
 final class ShortUrlIdentifier
@@ -42,6 +43,19 @@ final class ShortUrlIdentifier
         return new self($shortCode, $domain);
     }
 
+    public static function fromShortUrl(ShortUrl $shortUrl): self
+    {
+        $domain = $shortUrl->getDomain();
+        $domainAuthority = $domain !== null ? $domain->getAuthority() : null;
+
+        return new self($shortUrl->getShortCode(), $domainAuthority);
+    }
+
+    public static function fromShortCodeAndDomain(string $shortCode, ?string $domain = null): self
+    {
+        return new self($shortCode, $domain);
+    }
+
     public function shortCode(): string
     {
         return $this->shortCode;
diff --git a/module/Core/src/Repository/ShortUrlRepository.php b/module/Core/src/Repository/ShortUrlRepository.php
index eacf293b..a1b93f4d 100644
--- a/module/Core/src/Repository/ShortUrlRepository.php
+++ b/module/Core/src/Repository/ShortUrlRepository.php
@@ -4,6 +4,7 @@ declare(strict_types=1);
 
 namespace Shlinkio\Shlink\Core\Repository;
 
+use Doctrine\DBAL\LockMode;
 use Doctrine\ORM\Query\Expr\Join;
 use Doctrine\ORM\QueryBuilder;
 use Happyr\DoctrineSpecification\Repository\EntitySpecificationRepository;
@@ -11,6 +12,7 @@ use Happyr\DoctrineSpecification\Specification\Specification;
 use Shlinkio\Shlink\Common\Doctrine\Type\ChronosDateTimeType;
 use Shlinkio\Shlink\Common\Util\DateRange;
 use Shlinkio\Shlink\Core\Entity\ShortUrl;
+use Shlinkio\Shlink\Core\Model\ShortUrlIdentifier;
 use Shlinkio\Shlink\Core\Model\ShortUrlMeta;
 use Shlinkio\Shlink\Core\Model\ShortUrlsOrdering;
 use Shlinkio\Shlink\Importer\Model\ImportedShlinkUrl;
@@ -180,12 +182,24 @@ class ShortUrlRepository extends EntitySpecificationRepository implements ShortU
         return $qb->getQuery()->getOneOrNullResult();
     }
 
-    public function shortCodeIsInUse(string $slug, ?string $domain = null, ?Specification $spec = null): bool
+    public function shortCodeIsInUse(ShortUrlIdentifier $identifier, ?Specification $spec = null): bool
     {
-        $qb = $this->createFindOneQueryBuilder($slug, $domain, $spec);
-        $qb->select('COUNT(DISTINCT s.id)');
+        return $this->doShortCodeIsInUse($identifier, $spec, null);
+    }
 
-        return ((int) $qb->getQuery()->getSingleScalarResult()) > 0;
+    public function shortCodeIsInUseWithLock(ShortUrlIdentifier $identifier, ?Specification $spec = null): bool
+    {
+        return $this->doShortCodeIsInUse($identifier, $spec, LockMode::PESSIMISTIC_WRITE);
+    }
+
+    private function doShortCodeIsInUse(ShortUrlIdentifier $identifier, ?Specification $spec, ?int $lockMode): bool
+    {
+        $qb = $this->createFindOneQueryBuilder($identifier->shortCode(), $identifier->domain(), $spec);
+        $qb->select('s.id');
+
+        $query = $qb->getQuery()->setLockMode($lockMode);
+
+        return $query->getOneOrNullResult() !== null;
     }
 
     private function createFindOneQueryBuilder(string $slug, ?string $domain, ?Specification $spec): QueryBuilder
diff --git a/module/Core/src/Repository/ShortUrlRepositoryInterface.php b/module/Core/src/Repository/ShortUrlRepositoryInterface.php
index 5d8fa924..9b6dffc8 100644
--- a/module/Core/src/Repository/ShortUrlRepositoryInterface.php
+++ b/module/Core/src/Repository/ShortUrlRepositoryInterface.php
@@ -9,6 +9,7 @@ use Happyr\DoctrineSpecification\Repository\EntitySpecificationRepositoryInterfa
 use Happyr\DoctrineSpecification\Specification\Specification;
 use Shlinkio\Shlink\Common\Util\DateRange;
 use Shlinkio\Shlink\Core\Entity\ShortUrl;
+use Shlinkio\Shlink\Core\Model\ShortUrlIdentifier;
 use Shlinkio\Shlink\Core\Model\ShortUrlMeta;
 use Shlinkio\Shlink\Core\Model\ShortUrlsOrdering;
 use Shlinkio\Shlink\Importer\Model\ImportedShlinkUrl;
@@ -36,7 +37,9 @@ interface ShortUrlRepositoryInterface extends ObjectRepository, EntitySpecificat
 
     public function findOne(string $shortCode, ?string $domain = null, ?Specification $spec = null): ?ShortUrl;
 
-    public function shortCodeIsInUse(string $slug, ?string $domain, ?Specification $spec = null): bool;
+    public function shortCodeIsInUse(ShortUrlIdentifier $identifier, ?Specification $spec = null): bool;
+
+    public function shortCodeIsInUseWithLock(ShortUrlIdentifier $identifier, ?Specification $spec = null): bool;
 
     public function findOneMatching(ShortUrlMeta $meta): ?ShortUrl;
 
diff --git a/module/Core/src/Service/ShortUrl/ShortCodeHelper.php b/module/Core/src/Service/ShortUrl/ShortCodeHelper.php
index 3df4c016..83c3397e 100644
--- a/module/Core/src/Service/ShortUrl/ShortCodeHelper.php
+++ b/module/Core/src/Service/ShortUrl/ShortCodeHelper.php
@@ -6,6 +6,7 @@ namespace Shlinkio\Shlink\Core\Service\ShortUrl;
 
 use Doctrine\ORM\EntityManagerInterface;
 use Shlinkio\Shlink\Core\Entity\ShortUrl;
+use Shlinkio\Shlink\Core\Model\ShortUrlIdentifier;
 use Shlinkio\Shlink\Core\Repository\ShortUrlRepository;
 
 class ShortCodeHelper implements ShortCodeHelperInterface // TODO Rename to ShortCodeUniquenessHelper
@@ -19,13 +20,9 @@ class ShortCodeHelper implements ShortCodeHelperInterface // TODO Rename to Shor
 
     public function ensureShortCodeUniqueness(ShortUrl $shortUrlToBeCreated, bool $hasCustomSlug): bool
     {
-        $shortCode = $shortUrlToBeCreated->getShortCode();
-        $domain = $shortUrlToBeCreated->getDomain();
-        $domainAuthority = $domain !== null ? $domain->getAuthority() : null;
-
         /** @var ShortUrlRepository $repo */
         $repo = $this->em->getRepository(ShortUrl::class);
-        $otherShortUrlsExist = $repo->shortCodeIsInUse($shortCode, $domainAuthority);
+        $otherShortUrlsExist = $repo->shortCodeIsInUseWithLock(ShortUrlIdentifier::fromShortUrl($shortUrlToBeCreated));
 
         if (! $otherShortUrlsExist) {
             return true;
diff --git a/module/Core/src/Visit/VisitsStatsHelper.php b/module/Core/src/Visit/VisitsStatsHelper.php
index 1aa03c46..dfa00a4c 100644
--- a/module/Core/src/Visit/VisitsStatsHelper.php
+++ b/module/Core/src/Visit/VisitsStatsHelper.php
@@ -58,7 +58,7 @@ class VisitsStatsHelper implements VisitsStatsHelperInterface
 
         /** @var ShortUrlRepositoryInterface $repo */
         $repo = $this->em->getRepository(ShortUrl::class);
-        if (! $repo->shortCodeIsInUse($identifier->shortCode(), $identifier->domain(), $spec)) {
+        if (! $repo->shortCodeIsInUse($identifier, $spec)) {
             throw ShortUrlNotFoundException::fromNotFound($identifier);
         }
 
diff --git a/module/Core/test-db/Repository/ShortUrlRepositoryTest.php b/module/Core/test-db/Repository/ShortUrlRepositoryTest.php
index bd5b22d4..345e0911 100644
--- a/module/Core/test-db/Repository/ShortUrlRepositoryTest.php
+++ b/module/Core/test-db/Repository/ShortUrlRepositoryTest.php
@@ -11,6 +11,7 @@ use Shlinkio\Shlink\Common\Util\DateRange;
 use Shlinkio\Shlink\Core\Entity\Domain;
 use Shlinkio\Shlink\Core\Entity\ShortUrl;
 use Shlinkio\Shlink\Core\Entity\Visit;
+use Shlinkio\Shlink\Core\Model\ShortUrlIdentifier;
 use Shlinkio\Shlink\Core\Model\ShortUrlMeta;
 use Shlinkio\Shlink\Core\Model\ShortUrlsOrdering;
 use Shlinkio\Shlink\Core\Model\Visitor;
@@ -180,12 +181,18 @@ class ShortUrlRepositoryTest extends DatabaseTestCase
 
         $this->getEntityManager()->flush();
 
-        self::assertTrue($this->repo->shortCodeIsInUse('my-cool-slug'));
-        self::assertFalse($this->repo->shortCodeIsInUse('my-cool-slug', 'doma.in'));
-        self::assertFalse($this->repo->shortCodeIsInUse('slug-not-in-use'));
-        self::assertFalse($this->repo->shortCodeIsInUse('another-slug'));
-        self::assertFalse($this->repo->shortCodeIsInUse('another-slug', 'example.com'));
-        self::assertTrue($this->repo->shortCodeIsInUse('another-slug', 'doma.in'));
+        self::assertTrue($this->repo->shortCodeIsInUse(ShortUrlIdentifier::fromShortCodeAndDomain('my-cool-slug')));
+        self::assertFalse($this->repo->shortCodeIsInUse(
+            ShortUrlIdentifier::fromShortCodeAndDomain('my-cool-slug', 'doma.in'),
+        ));
+        self::assertFalse($this->repo->shortCodeIsInUse(ShortUrlIdentifier::fromShortCodeAndDomain('slug-not-in-use')));
+        self::assertFalse($this->repo->shortCodeIsInUse(ShortUrlIdentifier::fromShortCodeAndDomain('another-slug')));
+        self::assertFalse($this->repo->shortCodeIsInUse(
+            ShortUrlIdentifier::fromShortCodeAndDomain('another-slug', 'example.com'),
+        ));
+        self::assertTrue($this->repo->shortCodeIsInUse(
+            ShortUrlIdentifier::fromShortCodeAndDomain('another-slug', 'doma.in'),
+        ));
     }
 
     /** @test */
diff --git a/module/Core/test/Service/ShortUrl/ShortCodeHelperTest.php b/module/Core/test/Service/ShortUrl/ShortCodeHelperTest.php
index 047dbc96..ca3b463f 100644
--- a/module/Core/test/Service/ShortUrl/ShortCodeHelperTest.php
+++ b/module/Core/test/Service/ShortUrl/ShortCodeHelperTest.php
@@ -10,6 +10,7 @@ use Prophecy\PhpUnit\ProphecyTrait;
 use Prophecy\Prophecy\ObjectProphecy;
 use Shlinkio\Shlink\Core\Entity\Domain;
 use Shlinkio\Shlink\Core\Entity\ShortUrl;
+use Shlinkio\Shlink\Core\Model\ShortUrlIdentifier;
 use Shlinkio\Shlink\Core\Repository\ShortUrlRepository;
 use Shlinkio\Shlink\Core\Service\ShortUrl\ShortCodeHelper;
 
@@ -39,12 +40,12 @@ class ShortCodeHelperTest extends TestCase
         $callIndex = 0;
         $expectedCalls = 3;
         $repo = $this->prophesize(ShortUrlRepository::class);
-        $shortCodeIsInUse = $repo->shortCodeIsInUse('abc123', $expectedAuthority)->will(
-            function () use (&$callIndex, $expectedCalls) {
-                $callIndex++;
-                return $callIndex < $expectedCalls;
-            },
-        );
+        $shortCodeIsInUse = $repo->shortCodeIsInUseWithLock(
+            ShortUrlIdentifier::fromShortCodeAndDomain('abc123', $expectedAuthority),
+        )->will(function () use (&$callIndex, $expectedCalls) {
+            $callIndex++;
+            return $callIndex < $expectedCalls;
+        });
         $getRepo = $this->em->getRepository(ShortUrl::class)->willReturn($repo->reveal());
         $this->shortUrl->getDomain()->willReturn($domain);
 
@@ -66,7 +67,9 @@ class ShortCodeHelperTest extends TestCase
     public function inUseSlugReturnsError(): void
     {
         $repo = $this->prophesize(ShortUrlRepository::class);
-        $shortCodeIsInUse = $repo->shortCodeIsInUse('abc123', null)->willReturn(true);
+        $shortCodeIsInUse = $repo->shortCodeIsInUseWithLock(
+            ShortUrlIdentifier::fromShortCodeAndDomain('abc123'),
+        )->willReturn(true);
         $getRepo = $this->em->getRepository(ShortUrl::class)->willReturn($repo->reveal());
         $this->shortUrl->getDomain()->willReturn(null);
 
diff --git a/module/Core/test/Service/UrlShortenerTest.php b/module/Core/test/Service/UrlShortenerTest.php
index 7e319314..6bac432e 100644
--- a/module/Core/test/Service/UrlShortenerTest.php
+++ b/module/Core/test/Service/UrlShortenerTest.php
@@ -46,7 +46,6 @@ class UrlShortenerTest extends TestCase
             return $callback();
         });
         $repo = $this->prophesize(ShortUrlRepository::class);
-        $repo->shortCodeIsInUse(Argument::cetera())->willReturn(false);
         $this->em->getRepository(ShortUrl::class)->willReturn($repo->reveal());
 
         $this->shortCodeHelper = $this->prophesize(ShortCodeHelperInterface::class);
diff --git a/module/Core/test/Visit/VisitsStatsHelperTest.php b/module/Core/test/Visit/VisitsStatsHelperTest.php
index e6f067da..372bda9a 100644
--- a/module/Core/test/Visit/VisitsStatsHelperTest.php
+++ b/module/Core/test/Visit/VisitsStatsHelperTest.php
@@ -81,7 +81,9 @@ class VisitsStatsHelperTest extends TestCase
         $shortCode = '123ABC';
         $spec = $apiKey === null ? null : $apiKey->spec();
         $repo = $this->prophesize(ShortUrlRepositoryInterface::class);
-        $count = $repo->shortCodeIsInUse($shortCode, null, $spec)->willReturn(true);
+        $count = $repo->shortCodeIsInUse(ShortUrlIdentifier::fromShortCodeAndDomain($shortCode), $spec)->willReturn(
+            true,
+        );
         $this->em->getRepository(ShortUrl::class)->willReturn($repo->reveal())->shouldBeCalledOnce();
 
         $list = map(range(0, 1), fn () => Visit::forValidShortUrl(ShortUrl::createEmpty(), Visitor::emptyInstance()));
@@ -101,7 +103,9 @@ class VisitsStatsHelperTest extends TestCase
     {
         $shortCode = '123ABC';
         $repo = $this->prophesize(ShortUrlRepositoryInterface::class);
-        $count = $repo->shortCodeIsInUse($shortCode, null, null)->willReturn(false);
+        $count = $repo->shortCodeIsInUse(ShortUrlIdentifier::fromShortCodeAndDomain($shortCode), null)->willReturn(
+            false,
+        );
         $this->em->getRepository(ShortUrl::class)->willReturn($repo->reveal())->shouldBeCalledOnce();
 
         $this->expectException(ShortUrlNotFoundException::class);