diff --git a/src/Services/CacheProcessingService.php b/src/Services/CacheProcessingService.php
index 589bc3c..e4f9ea5 100644
--- a/src/Services/CacheProcessingService.php
+++ b/src/Services/CacheProcessingService.php
@@ -163,13 +163,13 @@ private function alreadyProcessed(string $className, int $id): bool
             return false;
         }
 
-        // We are in a "Draft" context, so we don't care whether or not the ProcessedUpdateDTO has been published or
-        // not. Its existence means that it has been processed
+        // We are in a "Draft" context, so we don't care whether the ProcessedUpdateDTO has been published or not. Its
+        // existence means that it has been processed
         if (!$this->shouldPublishUpdates()) {
             return true;
         }
 
-        // We are in a "Live" context, so we need to return whether or not this ProcessedUpdateDTO has been published
+        // We are in a "Live" context, so we need to return whether this ProcessedUpdateDTO has been published
         return $processedUpdate->isPublished();
     }
 
diff --git a/src/Services/ProcessedUpdatesService.php b/src/Services/ProcessedUpdatesService.php
index 044b10d..407098d 100644
--- a/src/Services/ProcessedUpdatesService.php
+++ b/src/Services/ProcessedUpdatesService.php
@@ -24,21 +24,15 @@ public function getProcessedUpdates(): array
 
     public function addProcessedUpdate(ProcessedUpdateDto $processedUpdate): void
     {
-        $this->processedUpdates[] = $processedUpdate;
+        $key = $this->getProcessedUpdateKey($processedUpdate->getClassName(), $processedUpdate->getId());
+        $this->processedUpdates[$key] = $processedUpdate;
     }
 
     public function findProcessedUpdate(string $className, int $id): ?ProcessedUpdateDto
     {
-        foreach ($this->processedUpdates as $processedUpdate) {
-            $classNameMatches = $processedUpdate->getClassName() === $className;
-            $idMatches = $processedUpdate->getId() === $id;
+        $key = $this->getProcessedUpdateKey($className, $id);
 
-            if ($idMatches && $classNameMatches) {
-                return $processedUpdate;
-            }
-        }
-
-        return null;
+        return $this->processedUpdates[$key] ?? null;
     }
 
     public function findOrCreateProcessedUpdate(string $className, int $id): ProcessedUpdateDto
@@ -50,9 +44,14 @@ public function findOrCreateProcessedUpdate(string $className, int $id): Process
         }
 
         $processedUpdate = new ProcessedUpdateDto($className, $id);
-        $this->processedUpdates[] = $processedUpdate;
+        $this->addProcessedUpdate($processedUpdate);
 
         return $processedUpdate;
     }
 
+    private function getProcessedUpdateKey(string $className, int $id): string
+    {
+        return sprintf('%s-%s', $className, $id);
+    }
+
 }
diff --git a/tests/Services/ProcessedUpdatesServiceTest.php b/tests/Services/ProcessedUpdatesServiceTest.php
index 013afc1..eb46a00 100644
--- a/tests/Services/ProcessedUpdatesServiceTest.php
+++ b/tests/Services/ProcessedUpdatesServiceTest.php
@@ -16,11 +16,11 @@ public function testAddProcessedUpdate(): void
         $this->assertCount(0, $service->getProcessedUpdates());
 
         $service->addProcessedUpdate(new ProcessedUpdateDto(Page::class, 99));
-        // There are no checks for duplication between DTOs
+        // Existing DTOs would be overridden if an identical record is added
         $service->addProcessedUpdate(new ProcessedUpdateDto(Page::class, 98));
         $service->addProcessedUpdate(new ProcessedUpdateDto(Page::class, 98));
 
-        $this->assertCount(3, $service->getProcessedUpdates());
+        $this->assertCount(2, $service->getProcessedUpdates());
     }
 
     public function testFindProcessedUpdate(): void