diff --git a/omf/fileio/geoh5.py b/omf/fileio/geoh5.py
index 278bd6a..ef7ab52 100644
--- a/omf/fileio/geoh5.py
+++ b/omf/fileio/geoh5.py
@@ -552,20 +552,27 @@ def collect_attributes(
         with fetch_h5_handle(workspace):
             if isinstance(element, UidModel):
                 values = element.array.array
+                ndvs = np.isnan(values)
 
-                if np.issubdtype(values.dtype, np.floating):
-                    values[np.isclose(values, FLOAT_NDV, atol=1e-45)] = np.nan
-                    values = values.astype(np.float32)
-                else:
+                if np.allclose(
+                    values[~ndvs].astype(np.int32), values[~ndvs], atol=2e-45
+                ):
+                    values[ndvs] = INTEGER_NDV
                     values = values.astype(np.int32)
+                else:
+                    values = values.astype(np.float32)
 
             else:
                 values = getattr(element, "values", None)
 
                 if np.issubdtype(values.dtype, np.floating):
-                    values[np.isnan(values)] = np.nan
+                    values[np.isclose(values, FLOAT_NDV, atol=2e-45)] = np.nan
                 else:
-                    values[np.isclose(values, INTEGER_NDV)] = 0
+                    # Convert to float with nan as no-data value not supporter by OMF
+                    ndvs = np.isclose(values, INTEGER_NDV)
+                    if np.any(ndvs):
+                        values = values.astype(np.float32)
+                        values[ndvs] = np.nan
 
             if values is not None:
                 conversion = _VALUE_MAP.get(type(self._parent), None)
diff --git a/tests/convert_volume_test.py b/tests/convert_volume_test.py
index b568509..b19be8d 100644
--- a/tests/convert_volume_test.py
+++ b/tests/convert_volume_test.py
@@ -13,7 +13,9 @@
 from pathlib import Path
 
 import numpy as np
+from geoh5py.data import IntegerData
 from geoh5py.objects import BlockModel
+from geoh5py.shared import INTEGER_NDV
 from geoh5py.workspace import Workspace
 
 import omf
@@ -177,11 +179,16 @@ def test_nan_values(tmp_path):
         values = np.random.randn(block.n_cells)
         values[block.centroids[:, 2] > 100] = np.nan  # Set some values to NaN
 
+        int_values = np.random.randint(0, 10, block.n_cells)
+        int_values[block.centroids[:, 2] > 100] = INTEGER_NDV  # Set some values to NaN
         block.add_data(
             {
                 "test_data": {
                     "values": values,
-                }
+                },
+                "test_int_data": {
+                    "values": int_values,
+                },
             }
         )
 
@@ -201,3 +208,9 @@ def test_nan_values(tmp_path):
             converter.from_omf(project)
             rec_data = out_ws.get_entity("test_data")[0]
             assert np.isnan(rec_data.values).sum() == np.isnan(values).sum()
+
+            rec_data = out_ws.get_entity("test_int_data")[0]
+            assert isinstance(rec_data, IntegerData)
+            assert (rec_data.values == INTEGER_NDV).sum() == (
+                block.centroids[:, 2] > 100
+            ).sum()