diff --git a/src/Entity/StorageLocation.php b/src/Entity/StorageLocation.php
index ac70127c8..97929329b 100644
--- a/src/Entity/StorageLocation.php
+++ b/src/Entity/StorageLocation.php
@@ -31,7 +31,7 @@ use Symfony\Component\Validator\Constraints as Assert;
  * @AuditLog\Auditable
  * @AppAssert\StorageLocation()
  */
-class StorageLocation
+class StorageLocation implements \Stringable
 {
     use Traits\TruncateStrings;
 
diff --git a/src/Validator/Constraints/StorageLocationValidator.php b/src/Validator/Constraints/StorageLocationValidator.php
index 960b27cd7..df4596522 100644
--- a/src/Validator/Constraints/StorageLocationValidator.php
+++ b/src/Validator/Constraints/StorageLocationValidator.php
@@ -4,6 +4,7 @@ namespace App\Validator\Constraints;
 
 use App\Entity;
 use App\Radio\Configuration;
+use Doctrine\ORM\EntityManagerInterface;
 use Exception;
 use Symfony\Component\Validator\Constraint;
 use Symfony\Component\Validator\ConstraintValidator;
@@ -11,11 +12,10 @@ use Symfony\Component\Validator\Exception\UnexpectedTypeException;
 
 class StorageLocationValidator extends ConstraintValidator
 {
-    protected Configuration $configuration;
-
-    public function __construct(Configuration $configuration)
-    {
-        $this->configuration = $configuration;
+    public function __construct(
+        protected Configuration $configuration,
+        protected EntityManagerInterface $em,
+    ) {
     }
 
     public function validate($storageLocation, Constraint $constraint): void
@@ -28,14 +28,52 @@ class StorageLocationValidator extends ConstraintValidator
             throw new UnexpectedTypeException($storageLocation, Entity\StorageLocation::class);
         }
 
+        // Ensure this storage location validates.
         try {
             $storageLocation->validate();
         } catch (Exception $e) {
-            $message = __('This storage location could not be validated: %s', '{{ error }}');
+            $message = __(
+                'Storage location %s could not be validated: %s',
+                '{{ storageLocation }}',
+                '{{ error }}'
+            );
 
             $this->context->buildViolation($message)
+                ->setParameter('{{ storageLocation }}', (string)$storageLocation)
                 ->setParameter('{{ error }}', $e->getMessage())
                 ->addViolation();
         }
+
+        // Ensure it's not a duplicate of other storage locations.
+        $qb = $this->em->createQueryBuilder()
+            ->select('sl')
+            ->from(Entity\StorageLocation::class, 'sl')
+            ->where('sl.type = :type')
+            ->setParameter('type', $storageLocation->getType())
+            ->andWhere('sl.adapter = :adapter')
+            ->setParameter('adapter', $storageLocation->getAdapter());
+
+        if (null !== $storageLocation->getId()) {
+            $qb->andWhere('sl.id != :id')
+                ->setParameter('id', $storageLocation->getId());
+        }
+
+        $storageLocationUri = $storageLocation->getUri();
+
+        /** @var Entity\StorageLocation $row */
+        foreach ($qb->getQuery()->toIterable() as $row) {
+            if ($row->getUri() === $storageLocationUri) {
+                $message = __(
+                    'Storage location %s already exists.',
+                    '{{ storageLocation }}',
+                );
+
+                $this->context->buildViolation($message)
+                    ->setParameter('{{ storageLocation }}', (string)$storageLocation)
+                    ->addViolation();
+
+                break;
+            }
+        }
     }
 }