diff --git a/CHANGELOG.md b/CHANGELOG.md
index a75e39ed..5eecc684 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -27,6 +27,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com), and this
 #### Fixed
 
 * [#665](https://github.com/shlinkio/shlink/issues/665) Fixed `base_url_redirect_to` simplified config option not being properly parsed.
+* [#663](https://github.com/shlinkio/shlink/issues/663) Fixed Shlink allowing short URLs to be created with an empty custom slug.
 
 
 ## 2.0.5 - 2020-02-09
diff --git a/composer.json b/composer.json
index 7b8bf39e..84707645 100644
--- a/composer.json
+++ b/composer.json
@@ -49,7 +49,7 @@
         "predis/predis": "^1.1",
         "pugx/shortid-php": "^0.5",
         "ramsey/uuid": "^3.9",
-        "shlinkio/shlink-common": "^2.7.0",
+        "shlinkio/shlink-common": "^2.8.0",
         "shlinkio/shlink-event-dispatcher": "^1.3",
         "shlinkio/shlink-installer": "^4.2.0",
         "shlinkio/shlink-ip-geolocation": "^1.3.1",
diff --git a/module/Core/src/Validation/ShortUrlMetaInputFilter.php b/module/Core/src/Validation/ShortUrlMetaInputFilter.php
index a71b4cc2..013edd8f 100644
--- a/module/Core/src/Validation/ShortUrlMetaInputFilter.php
+++ b/module/Core/src/Validation/ShortUrlMetaInputFilter.php
@@ -40,8 +40,14 @@ class ShortUrlMetaInputFilter extends InputFilter
         $validUntil->getValidatorChain()->attach(new Validator\Date(['format' => DateTime::ATOM]));
         $this->add($validUntil);
 
-        $customSlug = $this->createInput(self::CUSTOM_SLUG, false);
+        // FIXME The only way to enforce the NotEmpty validator to be evaluated when the value is provided but it's
+        //       empty, is by using the deprecated setContinueIfEmpty
+        $customSlug = $this->createInput(self::CUSTOM_SLUG, false)->setContinueIfEmpty(true);
         $customSlug->getFilterChain()->attach(new Validation\SluggerFilter());
+        $customSlug->getValidatorChain()->attach(new Validator\NotEmpty([
+            Validator\NotEmpty::STRING,
+            Validator\NotEmpty::SPACE,
+        ]));
         $this->add($customSlug);
 
         $this->add($this->createPositiveNumberInput(self::MAX_VISITS));
@@ -58,7 +64,7 @@ class ShortUrlMetaInputFilter extends InputFilter
     {
         $input = $this->createInput($name, false);
         $input->getValidatorChain()->attach(new Validator\Digits())
-              ->attach(new Validator\GreaterThan(['min' => $min, 'inclusive' => true]));
+                                   ->attach(new Validator\GreaterThan(['min' => $min, 'inclusive' => true]));
 
         return $input;
     }
diff --git a/module/Core/test/Model/ShortUrlMetaTest.php b/module/Core/test/Model/ShortUrlMetaTest.php
index fed2c662..7d0dd9b6 100644
--- a/module/Core/test/Model/ShortUrlMetaTest.php
+++ b/module/Core/test/Model/ShortUrlMetaTest.php
@@ -47,6 +47,15 @@ class ShortUrlMetaTest extends TestCase
         yield [[
             ShortUrlMetaInputFilter::SHORT_CODE_LENGTH => 3,
         ]];
+        yield [[
+            ShortUrlMetaInputFilter::CUSTOM_SLUG => '/',
+        ]];
+        yield [[
+            ShortUrlMetaInputFilter::CUSTOM_SLUG => '',
+        ]];
+        yield [[
+            ShortUrlMetaInputFilter::CUSTOM_SLUG => '   ',
+        ]];
     }
 
     /** @test */