diff --git a/docs/history.rst b/docs/history.rst
index 2dc362b..9c91204 100644
--- a/docs/history.rst
+++ b/docs/history.rst
@@ -3,6 +3,7 @@ History
 
 Latest
 -------
+- BUG: Update minimize dtype for int64 & int8 support (issue #139)
 
 0.4.2
 -------
diff --git a/geocube/rasterize.py b/geocube/rasterize.py
index 62680f0..3f6601e 100644
--- a/geocube/rasterize.py
+++ b/geocube/rasterize.py
@@ -7,11 +7,17 @@
 import numpy
 import odc.geo.geobox
 import pandas
+import rasterio
 import rasterio.features
 from numpy.typing import NDArray
+from packaging import version
 from rasterio.enums import MergeAlg
 from scipy.interpolate import Rbf, griddata
 
+_INT8_SUPPORTED = version.parse(rasterio.__gdal_version__) >= version.parse(
+    "3.7.0"
+) and version.parse(rasterio.__version__) >= version.parse("1.3.7")
+
 
 def _is_numeric(data_values: NDArray) -> bool:
     """
@@ -44,12 +50,9 @@ def _minimize_dtype(dtype: numpy.dtype, fill: float) -> numpy.dtype:
     Attempt to convert to float32 if fill is NaN and dtype is integer.
     """
     if numpy.issubdtype(dtype, numpy.integer):
-        if dtype.name == "int8":
-            # GDAL/rasterio doesn't support int8
+        if not _INT8_SUPPORTED and dtype.name == "int8":
+            # GDAL<3.7/rasterio<1.3.7 doesn't support int8
             dtype = numpy.dtype("int16")
-        if dtype.name == "int64":
-            # GDAL/rasterio doesn't support int64
-            dtype = numpy.dtype("float64")
         if numpy.isnan(fill):
             dtype = (
                 numpy.dtype("float64") if dtype.itemsize > 2 else numpy.dtype("float32")  # type: ignore
diff --git a/setup.cfg b/setup.cfg
index b63b71b..94507c3 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -37,7 +37,7 @@ install_requires =
     click>=6.0
     geopandas>=0.7
     odc_geo
-    rasterio
+    rasterio>=1.3
     rioxarray>=0.4
     scipy
     xarray>=0.17
diff --git a/test/integration/api/test_core_integration.py b/test/integration/api/test_core_integration.py
index 23399f2..8cd4b41 100644
--- a/test/integration/api/test_core_integration.py
+++ b/test/integration/api/test_core_integration.py
@@ -15,6 +15,7 @@
 from geocube.api.core import make_geocube
 from geocube.exceptions import VectorDataError
 from geocube.rasterize import (
+    _INT8_SUPPORTED,
     rasterize_image,
     rasterize_points_griddata,
     rasterize_points_radial,
@@ -101,7 +102,7 @@ def test_make_geocube__categorical(input_geodata, tmpdir):
         categorical_enums={"soil_type": ("sand", "silt", "clay")},
         fill=-9999.0,
     )
-    assert out_grid.soil_type.dtype.name == "int16"
+    assert out_grid.soil_type.dtype.name == "int8" if _INT8_SUPPORTED else "int16"
 
     # test writing to netCDF
     out_grid.to_netcdf(
@@ -451,7 +452,7 @@ def test_make_geocube__group_by__categorical(input_geodata, tmpdir):
         fill=-9999.0,
     )
 
-    assert out_grid.soil_type.dtype.name == "int16"
+    assert out_grid.soil_type.dtype.name == "int8" if _INT8_SUPPORTED else "int16"
     # test writing to netCDF
     out_grid.to_netcdf(
         tmpdir.mkdir("make_geocube_soil") / "soil_grid_group_categorical.nc"
@@ -816,7 +817,7 @@ def test_make_geocube__custom_rasterize_function__filter_null(
         ("uint16", float("NaN"), "float32"),
         ("int32", 0, "int32"),
         ("int32", float("NaN"), "float64"),
-        ("int64", 0, "float64"),
+        ("int64", 0, "int64"),
         ("int64", float("NaN"), "float64"),
     ],
 )