diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9a130887..fb66a3ac 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,11 @@ All notable changes to this project will be documented in this file.
 
 ## [Unreleased]
 
+- Disabled API Platform's legacy query-parameter validation system
+  (`legacy_query_parameter_validation: false`): its classes self-deprecate on load since 3.4,
+  spamming the `php` log channel on every request, and none of our filters declare the
+  constraints it enforces. The component is removed in API Platform 4.
+
 ## [3.0.0-rc6] - 2026-06-10
 
 - Fixed the 2.x → 3.0 screen client auto-upgrade path: images and the release tarball now also
diff --git a/config/packages/api_platform.yaml b/config/packages/api_platform.yaml
index 2ac60f9d..c55fecaa 100644
--- a/config/packages/api_platform.yaml
+++ b/config/packages/api_platform.yaml
@@ -39,6 +39,14 @@ api_platform:
     doctrine:
         enabled: true
 
+    validator:
+        # Don't register API Platform's legacy query-parameter validation
+        # system (ApiPlatform\ParameterValidator\...): its validator classes
+        # self-deprecate on load since 3.4, and none of our filters declare
+        # the constraints it enforces (all are required => false, no
+        # enum/bounds/length). The component is removed in API Platform 4.
+        legacy_query_parameter_validation: false
+
     swagger:
         versions: [3]
     #        api_keys:
@@ -57,7 +65,6 @@ api_platform:
         # The 4 following handlers are registered by default, keep those lines to prevent unexpected side effects
         Symfony\Component\Serializer\Exception\ExceptionInterface: 400 # Use a raw status code (recommended)
         ApiPlatform\Exception\InvalidArgumentException: !php/const Symfony\Component\HttpFoundation\Response::HTTP_BAD_REQUEST
-        ApiPlatform\ParameterValidator\Exception\ValidationExceptionInterface: 400
         Doctrine\ORM\OptimisticLockException: 409
 
         # Validation exception