diff --git a/xee/ext.py b/xee/ext.py
index 65bd9e0..680398e 100644
--- a/xee/ext.py
+++ b/xee/ext.py
@@ -331,6 +331,9 @@ def open_store_variable(self, name: str) -> xarray.Variable:
     x_dim_name, y_dim_name = self.dimension_names
     dimensions = [self.primary_dim_name, x_dim_name, y_dim_name]
     attrs = self._band_attrs(name)
+    # Convert 'data_type' attribute to string to make it valid for the dataset.
+    if attrs.get('data_type'):
+      attrs['data_type'] = str(attrs['data_type'])
     encoding = {
         'source': attrs['id'],
         'scale_factor': arr.scale,