diff --git a/tensorflow_graphics/geometry/convolution/utils.py b/tensorflow_graphics/geometry/convolution/utils.py
index f6bef95a4..25ec9f233 100644
--- a/tensorflow_graphics/geometry/convolution/utils.py
+++ b/tensorflow_graphics/geometry/convolution/utils.py
@@ -17,12 +17,16 @@
 from __future__ import division
 from __future__ import print_function
 
+from typing import Any, List, Optional, Tuple, Union
+
 import tensorflow as tf
 
 from tensorflow_graphics.util import shape
+from tensorflow_graphics.util import type_alias
 
 
-def _is_dynamic_shape(tensors):
+def _is_dynamic_shape(tensors: Union[List[type_alias.TensorLike],
+                                     Tuple[Any, tf.sparse.SparseTensor]]):
   """Helper function to test if any tensor in a list has a dynamic shape.
 
   Args:
@@ -36,7 +40,9 @@ def _is_dynamic_shape(tensors):
   return not all([shape.is_static(tensor.shape) for tensor in tensors])
 
 
-def check_valid_graph_convolution_input(data, neighbors, sizes):
+def check_valid_graph_convolution_input(data: type_alias.TensorLike,
+                                        neighbors: tf.sparse.SparseTensor,
+                                        sizes: type_alias.TensorLike):
   """Checks that the inputs are valid for graph convolution ops.
 
   Note:
@@ -86,7 +92,9 @@ def check_valid_graph_convolution_input(data, neighbors, sizes):
         broadcast_compatible=False)
 
 
-def check_valid_graph_pooling_input(data, pool_map, sizes):
+def check_valid_graph_pooling_input(data: type_alias.TensorLike,
+                                    pool_map: tf.sparse.SparseTensor,
+                                    sizes: type_alias.TensorLike):
   """Checks that the inputs are valid for graph pooling.
 
   Note:
@@ -136,7 +144,9 @@ def check_valid_graph_pooling_input(data, pool_map, sizes):
         broadcast_compatible=False)
 
 
-def check_valid_graph_unpooling_input(data, pool_map, sizes):
+def check_valid_graph_unpooling_input(data: type_alias.TensorLike,
+                                      pool_map: tf.sparse.SparseTensor,
+                                      sizes: type_alias.TensorLike):
   """Checks that the inputs are valid for graph unpooling.
 
   Note:
@@ -187,7 +197,9 @@ def check_valid_graph_unpooling_input(data, pool_map, sizes):
         broadcast_compatible=False)
 
 
-def flatten_batch_to_2d(data, sizes=None, name="utils_flatten_batch_to_2d"):
+def flatten_batch_to_2d(data: type_alias.TensorLike,
+                        sizes: type_alias.TensorLike = None,
+                        name: str = "utils_flatten_batch_to_2d"):
   """Reshapes a batch of 2d Tensors by flattening across the batch dimensions.
 
   Note:
@@ -286,10 +298,10 @@ def unflatten(flat, name="utils_unflatten"):
     return flat, unflatten
 
 
-def unflatten_2d_to_batch(data,
-                          sizes,
-                          max_rows=None,
-                          name="utils_unflatten_2d_to_batch"):
+def unflatten_2d_to_batch(data: type_alias.TensorLike,
+                          sizes: type_alias.TensorLike,
+                          max_rows: Optional[int] = None,
+                          name: str = "utils_unflatten_2d_to_batch"):
   r"""Reshapes a 2d Tensor into a batch of 2d Tensors.
 
   The `data` tensor with shape `[D1, D2]` will be mapped to a tensor with shape
@@ -369,10 +381,10 @@ def unflatten_2d_to_batch(data,
     return tf.scatter_nd(indices=mask_indices, updates=data, shape=output_shape)
 
 
-def convert_to_block_diag_2d(data,
-                             sizes=None,
-                             validate_indices=False,
-                             name="utils_convert_to_block_diag_2d"):
+def convert_to_block_diag_2d(data: tf.sparse.SparseTensor,
+                             sizes: Optional[type_alias.TensorLike] = None,
+                             validate_indices: bool = False,
+                             name: str = "utils_convert_to_block_diag_2d"):
   """Convert a batch of 2d SparseTensors to a 2d block diagonal SparseTensor.
 
   Note: