diff --git a/monai/data/wsi_datasets.py b/monai/data/wsi_datasets.py
index b1830018358..76ace77fc29 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/monai/handlers/probability_maps.py b/monai/handlers/probability_maps.py
index e21bd199f8e..eb0a51c6147 100644
--- a/monai/handlers/probability_maps.py
+++ b/monai/handlers/probability_maps.py
@@ -108,7 +108,9 @@ def __call__(self, engine: Engine) -> None:
         locs = engine.state.batch[CommonKeys.IMAGE].meta[ProbMapKeys.LOCATION]
         probs = engine.state.output[self.prob_key]
         for name, loc, prob in zip(names, locs, probs):
-            self.prob_map[name][tuple(loc)] = prob
+            # numpy 2.x rejects non-integer array indices, so coerce here for datasets that
+            # still supply float locations. The bundled WSI datasets already emit integers.
+            self.prob_map[name][tuple(int(i) for i in loc)] = prob
             with self.lock:
                 self.counter[name] -= 1
                 if self.counter[name] == 0:
diff --git a/tests/data/test_sliding_patch_wsi_dataset.py b/tests/data/test_sliding_patch_wsi_dataset.py
index 8e27f7ad0e4..aab390d298a 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 +250,9 @@ 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)
+                # `ProbMapProducer` uses these as probability-map indices, which numpy 2.x
+                # only accepts as integers.
+                self.assertTrue(np.issubdtype(sample["image"].meta[ProbMapKeys.LOCATION].dtype, np.integer))
 
 
 @skipUnless(has_cucim, "Requires cucim")
diff --git a/tests/handlers/test_handler_prob_map_producer.py b/tests/handlers/test_handler_prob_map_producer.py
index 063f7984cb8..cb7dbb8a94b 100644
--- a/tests/handlers/test_handler_prob_map_producer.py
+++ b/tests/handlers/test_handler_prob_map_producer.py
@@ -65,6 +65,21 @@ def __getitem__(self, index):
         return {"image": MetaTensor(x=image, meta=metadata), "pred": index + 1}
 
 
+class FloatLocationDataset(TestDataset):
+    """A test fixture whose probability-map locations are floats.
+
+    The bundled WSI datasets emit integer locations, so this stands in for a third-party
+    dataset that does not, which the handler still has to index the probability map with.
+    """
+
+    __test__ = False  # indicate to pytest that this class is not intended for collection
+
+    def __init__(self, name, size):
+        super().__init__(name, size)
+        for sample in self.data:
+            sample[ProbMapKeys.LOCATION.value] = sample[ProbMapKeys.LOCATION.value].astype(float)
+
+
 class TestEvaluator(Evaluator):
     __test__ = False  # indicate to pytest that this class is not intended for collection
 
@@ -73,10 +88,7 @@ def _iteration(self, engine, batchdata):
 
 
 class TestHandlerProbMapGenerator(unittest.TestCase):
-    @parameterized.expand([TEST_CASE_0, TEST_CASE_1, TEST_CASE_2])
-    def test_prob_map_generator(self, name, size):
-        # set up dataset
-        dataset = TestDataset(name, size)
+    def run_and_check(self, dataset, name, size):
         batch_size = 2
         data_loader = DataLoader(dataset, batch_size=batch_size)
 
@@ -106,6 +118,14 @@ def inference(engine, batch):
         self.assertListEqual(np.vstack(prob_map.nonzero()).T.tolist(), [[i, i + 1] for i in range(size)])
         self.assertListEqual(prob_map[prob_map.nonzero()].tolist(), [i + 1 for i in range(size)])
 
+    @parameterized.expand([TEST_CASE_0, TEST_CASE_1, TEST_CASE_2])
+    def test_prob_map_generator(self, name, size):
+        self.run_and_check(TestDataset(name, size), name, size)
+
+    @parameterized.expand([TEST_CASE_0, TEST_CASE_1, TEST_CASE_2])
+    def test_prob_map_generator_float_locations(self, name, size):
+        self.run_and_check(FloatLocationDataset(name, size), name, size)
+
 
 if __name__ == "__main__":
     unittest.main()