diff --git a/services/nginx/app/routes/moduleSelfServeRoute.php b/services/nginx/app/routes/moduleSelfServeRoute.php
index 4d25a500..e90de548 100644
--- a/services/nginx/app/routes/moduleSelfServeRoute.php
+++ b/services/nginx/app/routes/moduleSelfServeRoute.php
@@ -124,7 +124,7 @@ class moduleSelfServeRoute
             $lane_id = (int)$this->getParameter('lane_id');
             self::requireType($lane_id, self::type_int());
             self::requireMinValue($lane_id, 1);
-            $customer_scope = $this->requireInProgressWashDetailsAccess();
+            $customer_scope = $this->requireInProgressWashDetailsAccess($lane_id);
 
             $build_customer = static function (?int $customer_number): ?array {
                 if ($customer_number === null || $customer_number <= 0) {
@@ -1228,7 +1228,7 @@ class moduleSelfServeRoute
         ]);
     }
 
-    private function requireInProgressWashDetailsAccess(): ?int
+    private function requireInProgressWashDetailsAccess(int $lane_id): ?int
     {
         global $response;
 
@@ -1238,6 +1238,11 @@ class moduleSelfServeRoute
         }
 
         if (self::hasPermission('modules_selfserve_lane_wash_in_progress_view')) {
+            $department_lane = (new department_lanes_o())->select($lane_id);
+            if (!$department_lane->exists()) {
+                $response->error('Department lane not found', 404);
+            }
+            self::requireDepartmentAccess((string)$department_lane->department->value());
             return null;
         }
 
diff --git a/services/nginx/app/tests/Unit/Selfserve/SelfserveRouteWiringTest.php b/services/nginx/app/tests/Unit/Selfserve/SelfserveRouteWiringTest.php
index d5acfb96..2f6953c7 100644
--- a/services/nginx/app/tests/Unit/Selfserve/SelfserveRouteWiringTest.php
+++ b/services/nginx/app/tests/Unit/Selfserve/SelfserveRouteWiringTest.php
@@ -288,7 +288,9 @@ it('wires in-progress self-serve wash details endpoint', function (): void {
     expect($moduleSelfServeRoute)->toContain('/modules/self-serve/lane/wash/in-progress');
     expect($moduleSelfServeRoute)->toContain('modules_selfserve_lane_wash_in_progress_view');
     expect($moduleSelfServeRoute)->toContain('list_own_department_selfserve_vehicle_conditions');
-    expect($moduleSelfServeRoute)->toContain('requireInProgressWashDetailsAccess');
+    expect($moduleSelfServeRoute)->toContain('requireInProgressWashDetailsAccess($lane_id)');
+    expect($moduleSelfServeRoute)->toContain('(new department_lanes_o())->select($lane_id)');
+    expect($moduleSelfServeRoute)->toContain('self::requireDepartmentAccess((string)$department_lane->department->value())');
     expect($moduleSelfServeRoute)->toContain('scopeInProgressWashResponseForCustomer');
     expect($moduleSelfServeRoute)->toContain("'in_progress' => true");
     expect($moduleSelfServeRoute)->toContain("'in_progress' => false");