diff --git a/physicsnemo/models/figconvnet/figconvunet.py b/physicsnemo/models/figconvnet/figconvunet.py
index a027aced26..78c87f5699 100644
--- a/physicsnemo/models/figconvnet/figconvunet.py
+++ b/physicsnemo/models/figconvnet/figconvunet.py
@@ -135,7 +135,7 @@ def __init__(
         aabb_min: Tuple[float, float, float] = (0.0, 0.0, 0.0),
         voxel_size: Optional[float] = None,
         resolution_memory_format_pairs: List[
-            Tuple[GridFeaturesMemoryFormat, Tuple[int, int, int]]
+            Tuple[GridFeaturesMemoryFormat | str, Tuple[int, int, int]]
         ] = [
             (GridFeaturesMemoryFormat.b_xc_y_z, (2, 128, 128)),
             (GridFeaturesMemoryFormat.b_yc_x_z, (128, 2, 128)),
@@ -163,7 +163,10 @@ def __init__(
         self.point_feature_to_grids = nn.ModuleList()
         self.aabb_length = torch.tensor(aabb_max) - torch.tensor(aabb_min)
         self.min_voxel_edge_length = torch.tensor([np.inf, np.inf, np.inf])
+
         for mem_fmt, res in resolution_memory_format_pairs:
+            if isinstance(mem_fmt, str):
+                mem_fmt = GridFeaturesMemoryFormat[mem_fmt]
             compressed_axis = memory_format_to_axis_index[mem_fmt]
             compressed_spatial_dims.append(res[compressed_axis])
             to_grid = nn.Sequential(