diff --git a/stencils/pace/stencils/testing/grid.py b/stencils/pace/stencils/testing/grid.py
index 65ad8870..4cf623b1 100644
--- a/stencils/pace/stencils/testing/grid.py
+++ b/stencils/pace/stencils/testing/grid.py
@@ -504,7 +504,7 @@ def grid_data(self) -> "GridData":
             data = getattr(self, name)
             assert data is not None
 
-            quantity = self.quantity_factory.empty(dims=dims, units=units)
+            quantity = self.quantity_factory.zeros(dims=dims, units=units)
             if len(quantity.shape) == 3:
                 quantity.data[:] = data[:, :, : quantity.shape[2]]
             elif len(quantity.shape) == 2: