diff --git a/module/Core/src/ShortUrl/Model/Validation/ShortUrlInputFilter.php b/module/Core/src/ShortUrl/Model/Validation/ShortUrlInputFilter.php
index 90b7e8e8..762a9230 100644
--- a/module/Core/src/ShortUrl/Model/Validation/ShortUrlInputFilter.php
+++ b/module/Core/src/ShortUrl/Model/Validation/ShortUrlInputFilter.php
@@ -12,6 +12,7 @@ use Shlinkio\Shlink\Common\Validation;
 use Shlinkio\Shlink\Core\Options\UrlShortenerOptions;
 use Shlinkio\Shlink\Rest\Entity\ApiKey;
 
+use function is_string;
 use function preg_match;
 use function substr;
 
@@ -134,7 +135,8 @@ class ShortUrlInputFilter extends InputFilter
         return (new Validator\ValidatorChain())
             ->attach(new Validator\NotEmpty($emptyModifiers))
             ->attach(new Validator\Callback(
-                fn (?string $value) => ($allowNull && $value === null) || preg_match(LOOSE_URI_MATCHER, $value) === 1
+                // Non-strings is always allowed. Other validators will take care of those
+                static fn (mixed $value) => ! is_string($value) || preg_match(LOOSE_URI_MATCHER, $value) === 1,
             ));
     }
 }
diff --git a/module/Core/test/Importer/ImportedLinksProcessorTest.php b/module/Core/test/Importer/ImportedLinksProcessorTest.php
index d69d8480..95f7a7f8 100644
--- a/module/Core/test/Importer/ImportedLinksProcessorTest.php
+++ b/module/Core/test/Importer/ImportedLinksProcessorTest.php
@@ -67,9 +67,9 @@ class ImportedLinksProcessorTest extends TestCase
     public function newUrlsWithNoErrorsAreAllPersisted(): void
     {
         $urls = [
-            new ImportedShlinkUrl(ImportSource::BITLY, 'foo', [], Chronos::now(), null, 'foo', null),
-            new ImportedShlinkUrl(ImportSource::BITLY, 'bar', [], Chronos::now(), null, 'bar', 'foo'),
-            new ImportedShlinkUrl(ImportSource::BITLY, 'baz', [], Chronos::now(), null, 'baz', null),
+            new ImportedShlinkUrl(ImportSource::BITLY, 'https://foo', [], Chronos::now(), null, 'foo', null),
+            new ImportedShlinkUrl(ImportSource::BITLY, 'https://bar', [], Chronos::now(), null, 'bar', 'foo'),
+            new ImportedShlinkUrl(ImportSource::BITLY, 'https://baz', [], Chronos::now(), null, 'baz', null),
         ];
         $expectedCalls = count($urls);
 
@@ -90,9 +90,9 @@ class ImportedLinksProcessorTest extends TestCase
     public function newUrlsWithErrorsAreSkipped(): void
     {
         $urls = [
-            new ImportedShlinkUrl(ImportSource::BITLY, 'foo', [], Chronos::now(), null, 'foo', null),
-            new ImportedShlinkUrl(ImportSource::BITLY, 'bar', [], Chronos::now(), null, 'bar', 'foo'),
-            new ImportedShlinkUrl(ImportSource::BITLY, 'baz', [], Chronos::now(), null, 'baz', null),
+            new ImportedShlinkUrl(ImportSource::BITLY, 'https://foo', [], Chronos::now(), null, 'foo', null),
+            new ImportedShlinkUrl(ImportSource::BITLY, 'https://bar', [], Chronos::now(), null, 'bar', 'foo'),
+            new ImportedShlinkUrl(ImportSource::BITLY, 'https://baz', [], Chronos::now(), null, 'baz', null),
         ];
 
         $this->em->method('getRepository')->with(ShortUrl::class)->willReturn($this->repo);
@@ -126,8 +126,10 @@ class ImportedLinksProcessorTest extends TestCase
 
         $this->em->method('getRepository')->with(ShortUrl::class)->willReturn($this->repo);
         $this->repo->expects($this->exactly(count($urls)))->method('findOneByImportedUrl')->willReturnCallback(
-            fn (ImportedShlinkUrl $url): ?ShortUrl
-                => contains(['foo', 'baz2', 'baz3'], $url->longUrl) ? ShortUrl::fromImport($url, true) : null,
+            fn (ImportedShlinkUrl $url): ?ShortUrl => contains(
+                ['https://foo', 'https://baz2', 'https://baz3'],
+                $url->longUrl,
+            ) ? ShortUrl::fromImport($url, true) : null,
         );
         $this->shortCodeHelper->expects($this->exactly(2))->method('ensureShortCodeUniqueness')->willReturn(true);
         $this->em->expects($this->exactly(2))->method('persist')->with($this->isInstanceOf(ShortUrl::class));
@@ -143,11 +145,11 @@ class ImportedLinksProcessorTest extends TestCase
     public function nonUniqueShortCodesAreAskedToUser(): void
     {
         $urls = [
-            new ImportedShlinkUrl(ImportSource::BITLY, 'foo', [], Chronos::now(), null, 'foo', null),
-            new ImportedShlinkUrl(ImportSource::BITLY, 'bar', [], Chronos::now(), null, 'bar', null),
-            new ImportedShlinkUrl(ImportSource::BITLY, 'baz', [], Chronos::now(), null, 'baz', 'foo'),
-            new ImportedShlinkUrl(ImportSource::BITLY, 'baz2', [], Chronos::now(), null, 'baz2', null),
-            new ImportedShlinkUrl(ImportSource::BITLY, 'baz3', [], Chronos::now(), null, 'baz3', 'bar'),
+            new ImportedShlinkUrl(ImportSource::BITLY, 'https://foo', [], Chronos::now(), null, 'foo', null),
+            new ImportedShlinkUrl(ImportSource::BITLY, 'https://bar', [], Chronos::now(), null, 'bar', null),
+            new ImportedShlinkUrl(ImportSource::BITLY, 'https://baz', [], Chronos::now(), null, 'baz', 'foo'),
+            new ImportedShlinkUrl(ImportSource::BITLY, 'https://baz2', [], Chronos::now(), null, 'baz2', null),
+            new ImportedShlinkUrl(ImportSource::BITLY, 'https://baz3', [], Chronos::now(), null, 'baz3', 'bar'),
         ];
 
         $this->em->method('getRepository')->with(ShortUrl::class)->willReturn($this->repo);
@@ -191,7 +193,7 @@ class ImportedLinksProcessorTest extends TestCase
     {
         $now = Chronos::now();
         $createImportedUrl = static fn (array $visits) =>
-            new ImportedShlinkUrl(ImportSource::BITLY, 's', [], $now, null, 's', null, $visits);
+            new ImportedShlinkUrl(ImportSource::BITLY, 'https://s', [], $now, null, 's', null, $visits);
 
         yield 'new short URL' => [$createImportedUrl([
             new ImportedShlinkVisit('', '', $now, null),
diff --git a/module/Core/test/ShortUrl/Entity/ShortUrlTest.php b/module/Core/test/ShortUrl/Entity/ShortUrlTest.php
index 4a11d26a..bd83fd9a 100644
--- a/module/Core/test/ShortUrl/Entity/ShortUrlTest.php
+++ b/module/Core/test/ShortUrl/Entity/ShortUrlTest.php
@@ -98,26 +98,26 @@ class ShortUrlTest extends TestCase
 
         $shortUrl->update(ShortUrlEdition::fromRawData([
             ShortUrlInputFilter::DEVICE_LONG_URLS => [
-                DeviceType::ANDROID->value => 'android',
-                DeviceType::IOS->value => 'ios',
+                DeviceType::ANDROID->value => 'https://android',
+                DeviceType::IOS->value => 'https://ios',
             ],
         ]));
         self::assertEquals([
-            DeviceType::ANDROID->value => 'android',
-            DeviceType::IOS->value => 'ios',
+            DeviceType::ANDROID->value => 'https://android',
+            DeviceType::IOS->value => 'https://ios',
             DeviceType::DESKTOP->value => null,
         ], $shortUrl->deviceLongUrls());
 
         $shortUrl->update(ShortUrlEdition::fromRawData([
             ShortUrlInputFilter::DEVICE_LONG_URLS => [
                 DeviceType::ANDROID->value => null,
-                DeviceType::DESKTOP->value => 'desktop',
+                DeviceType::DESKTOP->value => 'https://desktop',
             ],
         ]));
         self::assertEquals([
             DeviceType::ANDROID->value => null,
-            DeviceType::IOS->value => 'ios',
-            DeviceType::DESKTOP->value => 'desktop',
+            DeviceType::IOS->value => 'https://ios',
+            DeviceType::DESKTOP->value => 'https://desktop',
         ], $shortUrl->deviceLongUrls());
 
         $shortUrl->update(ShortUrlEdition::fromRawData([
@@ -129,7 +129,7 @@ class ShortUrlTest extends TestCase
         self::assertEquals([
             DeviceType::ANDROID->value => null,
             DeviceType::IOS->value => null,
-            DeviceType::DESKTOP->value => 'desktop',
+            DeviceType::DESKTOP->value => 'https://desktop',
         ], $shortUrl->deviceLongUrls());
     }
 
@@ -139,7 +139,7 @@ class ShortUrlTest extends TestCase
         $range = range(1, 1000); // Use a "big" number to reduce false negatives
         $allFor = static fn (ShortUrlMode $mode): bool => every($range, static function () use ($mode): bool {
             $shortUrl = ShortUrl::create(ShortUrlCreation::fromRawData(
-                [ShortUrlInputFilter::LONG_URL => 'foo'],
+                [ShortUrlInputFilter::LONG_URL => 'https://foo'],
                 new UrlShortenerOptions(mode: $mode),
             ));
             $shortCode = $shortUrl->getShortCode();
diff --git a/module/Core/test/ShortUrl/Model/ShortUrlCreationTest.php b/module/Core/test/ShortUrl/Model/ShortUrlCreationTest.php
index 6712c49f..adecf9e9 100644
--- a/module/Core/test/ShortUrl/Model/ShortUrlCreationTest.php
+++ b/module/Core/test/ShortUrl/Model/ShortUrlCreationTest.php
@@ -33,37 +33,37 @@ class ShortUrlCreationTest extends TestCase
     {
         yield [[]];
         yield [[
-            ShortUrlInputFilter::LONG_URL => 'foo',
+            ShortUrlInputFilter::LONG_URL => 'https://foo',
             ShortUrlInputFilter::VALID_SINCE => '',
             ShortUrlInputFilter::VALID_UNTIL => '',
             ShortUrlInputFilter::CUSTOM_SLUG => 'foobar',
             ShortUrlInputFilter::MAX_VISITS => 'invalid',
         ]];
         yield [[
-            ShortUrlInputFilter::LONG_URL => 'foo',
+            ShortUrlInputFilter::LONG_URL => 'https://foo',
             ShortUrlInputFilter::VALID_SINCE => '2017',
             ShortUrlInputFilter::MAX_VISITS => 5,
         ]];
         yield [[
-            ShortUrlInputFilter::LONG_URL => 'foo',
+            ShortUrlInputFilter::LONG_URL => 'https://foo',
             ShortUrlInputFilter::VALID_SINCE => new stdClass(),
             ShortUrlInputFilter::VALID_UNTIL => 'foo',
         ]];
         yield [[
-            ShortUrlInputFilter::LONG_URL => 'foo',
+            ShortUrlInputFilter::LONG_URL => 'https://foo',
             ShortUrlInputFilter::VALID_UNTIL => 500,
             ShortUrlInputFilter::DOMAIN => 4,
         ]];
         yield [[
-            ShortUrlInputFilter::LONG_URL => 'foo',
+            ShortUrlInputFilter::LONG_URL => 'https://foo',
             ShortUrlInputFilter::SHORT_CODE_LENGTH => 3,
         ]];
         yield [[
-            ShortUrlInputFilter::LONG_URL => 'foo',
+            ShortUrlInputFilter::LONG_URL => 'https://foo',
             ShortUrlInputFilter::CUSTOM_SLUG => '',
         ]];
         yield [[
-            ShortUrlInputFilter::LONG_URL => 'foo',
+            ShortUrlInputFilter::LONG_URL => 'https://foo',
             ShortUrlInputFilter::CUSTOM_SLUG => '   ',
         ]];
         yield [[
@@ -73,33 +73,36 @@ class ShortUrlCreationTest extends TestCase
             ShortUrlInputFilter::LONG_URL => null,
         ]];
         yield [[
-            ShortUrlInputFilter::LONG_URL => 'foo',
+            ShortUrlInputFilter::LONG_URL => 'missing_schema',
+        ]];
+        yield [[
+            ShortUrlInputFilter::LONG_URL => 'https://foo',
             ShortUrlInputFilter::DEVICE_LONG_URLS => [
                 'invalid' => 'https://shlink.io',
             ],
         ]];
         yield [[
-            ShortUrlInputFilter::LONG_URL => 'foo',
+            ShortUrlInputFilter::LONG_URL => 'https://foo',
             ShortUrlInputFilter::DEVICE_LONG_URLS => [
                 DeviceType::DESKTOP->value => '',
             ],
         ]];
         yield [[
-            ShortUrlInputFilter::LONG_URL => 'foo',
+            ShortUrlInputFilter::LONG_URL => 'https://foo',
             ShortUrlInputFilter::DEVICE_LONG_URLS => [
                 DeviceType::DESKTOP->value => null,
             ],
         ]];
         yield [[
-            ShortUrlInputFilter::LONG_URL => 'foo',
+            ShortUrlInputFilter::LONG_URL => 'https://foo',
             ShortUrlInputFilter::DEVICE_LONG_URLS => [
                 DeviceType::IOS->value => '   ',
             ],
         ]];
         yield [[
-            ShortUrlInputFilter::LONG_URL => 'foo',
+            ShortUrlInputFilter::LONG_URL => 'https://foo',
             ShortUrlInputFilter::DEVICE_LONG_URLS => [
-                DeviceType::IOS->value => 'bar',
+                DeviceType::IOS->value => 'https://bar',
                 DeviceType::ANDROID->value => [],
             ],
         ]];