diff --git a/CHANGELOG.md b/CHANGELOG.md
index 127fbf12f..6fd185d70 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,11 @@ All notable changes to this project will be documented in this file.
 
 ## [Unreleased]
 
+- De-flaked `RelationsChecksumListenerTest`: the media-checksum tests now use a dedicated
+  fixture slide (`slide_media_checksum_test`) with known media and no playlist membership.
+  Previously an unordered `findOneBy()` could return the media-less `slide_abc_notified`
+  (crashing on the missing `media` checksum key) or a slide deleted earlier in the class by
+  `testRemoveSlide()`, which removes a random-`createdAt` fixture slide from the shared DB.
 - Fixed the 2.x → 3.0 screen client auto-upgrade path: ship a copy of `release.json` at the
   deprecated `/client/release.json` location polled by 2.x clients. Without it the catch-all
   `/client` route answered with the SPA's HTML and already-running 2.x screens never detected
diff --git a/fixtures/slide.yaml b/fixtures/slide.yaml
index 782e8d2a0..7c8c0cf7f 100644
--- a/fixtures/slide.yaml
+++ b/fixtures/slide.yaml
@@ -37,3 +37,10 @@ App\Entity\Tenant\Slide:
   slide_relations_checksum_test (extends slide):
     title: "slide_relations_checksum_test"
     tenant: "@tenant_xyz"
+  # Dedicated to the media tests in RelationsChecksumListenerTest: known media
+  # (two distinct, so one can be removed and the 'media' checksum key remains)
+  # and on no playlist, so testRemoveSlide() can never delete it.
+  slide_media_checksum_test (extends slide):
+    title: "slide_media_checksum_test"
+    tenant: "@tenant_abc"
+    media: ["@media_abc_1", "@media_abc_2"]
diff --git a/tests/Api/SlidesTest.php b/tests/Api/SlidesTest.php
index 492ef980b..d4a3e614c 100644
--- a/tests/Api/SlidesTest.php
+++ b/tests/Api/SlidesTest.php
@@ -22,7 +22,7 @@ public function testGetCollection(): void
             '@context' => '/contexts/Slide',
             '@id' => '/v2/slides',
             '@type' => 'hydra:Collection',
-            'hydra:totalItems' => 61,
+            'hydra:totalItems' => 62,
             'hydra:view' => [
                 '@id' => '/v2/slides?itemsPerPage=10&page=1',
                 '@type' => 'hydra:PartialCollectionView',
diff --git a/tests/EventListener/RelationsChecksumListenerTest.php b/tests/EventListener/RelationsChecksumListenerTest.php
index 6619b007a..efe2dd556 100644
--- a/tests/EventListener/RelationsChecksumListenerTest.php
+++ b/tests/EventListener/RelationsChecksumListenerTest.php
@@ -210,9 +210,8 @@ public function testPersistSlide(): void
 
     public function testUpdateMedia(): void
     {
-        $tenant = $this->em->getRepository(Tenant::class)->findOneBy(['tenantKey' => 'ABC']);
         /** @var Tenant\Slide $slide */
-        $slide = $this->em->getRepository(Tenant\Slide::class)->findOneBy(['tenant' => $tenant]);
+        $slide = $this->em->getRepository(Tenant\Slide::class)->findOneBy(['title' => 'slide_media_checksum_test']);
 
         $before = $slide->getRelationsChecksum()['media'];
 
@@ -527,7 +526,7 @@ public function testAddMediaToSlideUpdatesChecksum(): void
     {
         $tenant = $this->em->getRepository(Tenant::class)->findOneBy(['tenantKey' => 'ABC']);
         /** @var Tenant\Slide $slide */
-        $slide = $this->em->getRepository(Tenant\Slide::class)->findOneBy(['tenant' => $tenant]);
+        $slide = $this->em->getRepository(Tenant\Slide::class)->findOneBy(['title' => 'slide_media_checksum_test']);
         $beforeChecksum = $slide->getRelationsChecksum()['media'];
 
         // Find a media not already on this slide
@@ -553,9 +552,8 @@ public function testAddMediaToSlideUpdatesChecksum(): void
 
     public function testRemoveMediaFromSlideUpdatesChecksum(): void
     {
-        $tenant = $this->em->getRepository(Tenant::class)->findOneBy(['tenantKey' => 'ABC']);
         /** @var Tenant\Slide $slide */
-        $slide = $this->em->getRepository(Tenant\Slide::class)->findOneBy(['tenant' => $tenant]);
+        $slide = $this->em->getRepository(Tenant\Slide::class)->findOneBy(['title' => 'slide_media_checksum_test']);
         $this->assertGreaterThan(0, $slide->getMedia()->count());
 
         $beforeChecksum = $slide->getRelationsChecksum()['media'];
@@ -566,6 +564,8 @@ public function testRemoveMediaFromSlideUpdatesChecksum(): void
         $this->em->flush();
 
         $this->em->refresh($slide);
+        // The fixture slide has two media, so one remains after the removal and
+        // the 'media' checksum key still exists.
         $this->assertNotEquals($beforeChecksum, $slide->getRelationsChecksum()['media']);
         $this->assertFalse($slide->isChanged());
     }