diff --git a/src/Form/Type/Api/EditPackageType.php b/src/Form/Type/Api/EditPackageType.php
index 24e8f996..9cb29446 100644
--- a/src/Form/Type/Api/EditPackageType.php
+++ b/src/Form/Type/Api/EditPackageType.php
@@ -36,6 +36,7 @@ public function buildForm(FormBuilderInterface $builder, array $options): void
                 'label' => 'Keep last releases',
                 'help' => 'Number of last releases that will be downloaded. Put "0" to download all.',
                 'constraints' => [
+                    new NotBlank(),
                     new PositiveOrZero(),
                 ],
             ]);
diff --git a/src/Form/Type/Organization/EditPackageType.php b/src/Form/Type/Organization/EditPackageType.php
index dfcfe170..c917fc5e 100644
--- a/src/Form/Type/Organization/EditPackageType.php
+++ b/src/Form/Type/Organization/EditPackageType.php
@@ -35,6 +35,7 @@ public function buildForm(FormBuilderInterface $builder, array $options): void
                 'label' => 'Keep last releases',
                 'help' => 'Number of last releases that will be downloaded. Put "0" to download all.',
                 'constraints' => [
+                    new NotBlank(),
                     new PositiveOrZero(),
                 ],
             ])