diff --git a/tests/Service/TravelDataServiceTest.php b/tests/Service/TravelDataServiceTest.php
index 80a3389..dba858f 100644
--- a/tests/Service/TravelDataServiceTest.php
+++ b/tests/Service/TravelDataServiceTest.php
@@ -290,6 +290,40 @@ class TravelDataServiceTest extends TestCase
         ], $result);
     }
 
+    public function testGenerateFilesMapIsMemoizedWithinRequest(): void
+    {
+        $dateId = 12345;
+        $hotelId = 67890;
+        $mapping = [
+            $dateId => [
+                'id' => $dateId,
+                'hotels' => [
+                    $hotelId => ['id' => $hotelId, 'name' => 'Test Hotel'],
+                ],
+            ],
+        ];
+
+        // Both existsLocally() calls go through generateFilesMap(); the underlying
+        // loader and snapshot service must each be invoked only once.
+        $this->travelSnapshotService
+            ->expects($this->exactly(2))
+            ->method('exists')
+            ->willReturn(false);
+
+        $this->travelLoader
+            ->expects($this->once())
+            ->method('generateFilesMap')
+            ->willReturn($mapping);
+
+        $this->travelSnapshotService
+            ->expects($this->once())
+            ->method('generateMapping')
+            ->willReturn([]);
+
+        $this->service->existsLocally($dateId, $hotelId);
+        $this->service->existsLocally($dateId, $hotelId);
+    }
+
     public function testGetTravelDataFromLocalPrefersSnapshot(): void
     {
         $dateId = 12345;