diff --git a/trollimage/colormap.py b/trollimage/colormap.py
index 015ea5db..97dc5f0e 100644
--- a/trollimage/colormap.py
+++ b/trollimage/colormap.py
@@ -134,7 +134,7 @@ def palettize(arr, colors, values):
 
 def _palettize_dask(darr, colors, values):
     """Apply a palette to a dask array."""
-    return darr.map_blocks(_palettize, values, dtype=colors.dtype)
+    return darr.map_blocks(_palettize, values, dtype=int)
 
 
 def _palettize(arr, values):
diff --git a/trollimage/tests/test_colormap.py b/trollimage/tests/test_colormap.py
index bbc2f530..ac8585f5 100644
--- a/trollimage/tests/test_colormap.py
+++ b/trollimage/tests/test_colormap.py
@@ -125,6 +125,7 @@ def test_palettize_dask(self):
         self.assertTrue(np.allclose(channels.compute(), [[0, 1, 2, 3],
                                                          [0, 1, 2, 3],
                                                          [0, 1, 2, 3]]))
+        assert channels.dtype == int
 
     def test_set_range(self):
         """Test set_range."""