diff --git a/src/aws/osml/model_runner/tile_worker/tile_worker_utils.py b/src/aws/osml/model_runner/tile_worker/tile_worker_utils.py
index 036e3fc8..99797455 100755
--- a/src/aws/osml/model_runner/tile_worker/tile_worker_utils.py
+++ b/src/aws/osml/model_runner/tile_worker/tile_worker_utils.py
@@ -103,7 +103,7 @@ def process_tiles(
     """
 
     tile_array = generate_crops(
-        region_request.region_bounds,  # type: ignore[arg-type]
+        region_request.region_bounds,
         region_request.tile_size,
         region_request.tile_overlap,
     )
diff --git a/test/aws/osml/model_runner/tile_worker/test_tile_worker_utils.py b/test/aws/osml/model_runner/tile_worker/test_tile_worker_utils.py
index 69802427..6e3238a1 100755
--- a/test/aws/osml/model_runner/tile_worker/test_tile_worker_utils.py
+++ b/test/aws/osml/model_runner/tile_worker/test_tile_worker_utils.py
@@ -63,21 +63,17 @@ def test_setup_tile_workers_exception(self, mock_service_config, mock_tile_worke
             # with self.assertRaises(ValueError):
             setup_tile_workers(mock_region_request, mock_sensor_model, mock_elevation_model)
 
-    @patch("aws.osml.model_runner.tile_worker.tile_worker_utils.ServiceConfig", autospec=True)
     def test_process_tiles(
         self,
-        mock_service_config,
     ):
         from aws.osml.gdal.gdal_utils import load_gdal_dataset
         from aws.osml.model_runner.api import RegionRequest
         from aws.osml.model_runner.tile_worker.tile_worker_utils import process_tiles, setup_tile_workers
 
-        mock_num_tile_workers = 4
-        mock_service_config.workers = mock_num_tile_workers
         mock_region_request = RegionRequest(
             {
                 "tile_size": (10, 10),
-                "tile_overlap": (1, 1),
+                "tile_overlap": (0, 0),
                 "tile_format": "NITF",
                 "image_id": "1",
                 "image_url": "/mock/path",
@@ -91,7 +87,7 @@ def test_process_tiles(
         mock_elevation_model = None
         work_queue, tile_worker_list = setup_tile_workers(mock_region_request, sensor_model, mock_elevation_model)
 
-        assert 25, 0 == process_tiles(
+        completed_tiles, failed_tiles = process_tiles(
             region_request=mock_region_request,
             tile_queue=work_queue,
             tile_workers=tile_worker_list,
@@ -99,6 +95,9 @@ def test_process_tiles(
             sensor_model=sensor_model,
         )
 
+        assert completed_tiles == 25
+        assert failed_tiles == 0
+
     def test_chip_generator(self):
         from aws.osml.model_runner.tile_worker.tile_worker_utils import generate_crops