diff --git a/monai/data/wsi_datasets.py b/monai/data/wsi_datasets.py
index b183001835..76ace77fc2 100644
--- a/monai/data/wsi_datasets.py
+++ b/monai/data/wsi_datasets.py
@@ -306,7 +306,7 @@ def _evaluate_patch_locations(self, sample):
             )
         )
         # convert locations to mask_location
-        mask_locations = np.round((patch_locations + patch_size_0 // 2) / float(mask_ratio))
+        mask_locations = np.round((patch_locations + patch_size_0 // 2) / float(mask_ratio)).astype(int)
 
         # fill out samples with location and metadata
         sample[WSIPatchKeys.SIZE.value] = patch_size
diff --git a/tests/data/test_sliding_patch_wsi_dataset.py b/tests/data/test_sliding_patch_wsi_dataset.py
index 8e27f7ad0e..63eb5da0ef 100644
--- a/tests/data/test_sliding_patch_wsi_dataset.py
+++ b/tests/data/test_sliding_patch_wsi_dataset.py
@@ -21,7 +21,7 @@
 from parameterized import parameterized
 
 from monai.data import SlidingPatchWSIDataset
-from monai.utils import WSIPatchKeys, optional_import, set_determinism
+from monai.utils import ProbMapKeys, WSIPatchKeys, optional_import, set_determinism
 from tests.test_utils import download_url_or_skip_test, testing_data_config
 
 set_determinism(0)
@@ -250,6 +250,8 @@ def test_read_patches_large(self, input_parameters, expected):
                 steps = [round(expected[i]["ratio"] * s) for s in expected[i]["patch_size"]]
                 expected_location = tuple(expected[i]["step_loc"][j] * steps[j] for j in range(len(steps)))
                 assert_array_equal(sample["image"].meta[WSIPatchKeys.LOCATION], expected_location)
+                mask_location = np.asarray(sample["image"].meta[ProbMapKeys.LOCATION])
+                self.assertTrue(np.issubdtype(mask_location.dtype, np.integer))
 
 
 @skipUnless(has_cucim, "Requires cucim")