diff --git a/captum/attr/_core/layer/internal_influence.py b/captum/attr/_core/layer/internal_influence.py
index 47b69ffb2..a0bbffee2 100644
--- a/captum/attr/_core/layer/internal_influence.py
+++ b/captum/attr/_core/layer/internal_influence.py
@@ -1,7 +1,7 @@
 #!/usr/bin/env python3
 
 # pyre-strict
-from typing import Any, Callable, Dict, List, Optional, Tuple, Union
+from typing import Any, Callable, cast, Dict, List, Optional, Tuple, Union
 
 import torch
 from captum._utils.common import (
@@ -41,8 +41,7 @@ class InternalInfluence(LayerAttribution, GradientAttribution):
 
     def __init__(
         self,
-        # pyre-fixme[24]: Generic type `Callable` expects 2 type parameters.
-        forward_func: Callable,
+        forward_func: Callable[..., Tensor],
         layer: Module,
         device_ids: Union[None, List[int]] = None,
     ) -> None:
@@ -293,7 +292,7 @@ def _attribute(
         # Returns gradient of output with respect to hidden layer.
         layer_gradients, _ = compute_layer_gradients_and_eval(
             forward_fn=self.forward_func,
-            layer=self.layer,
+            layer=cast(Module, self.layer),
             inputs=scaled_features_tpl,
             target_ind=expanded_target,
             additional_forward_args=input_additional_args,
@@ -304,9 +303,7 @@ def _attribute(
         # flattening grads so that we can multiply it with step-size
         # calling contiguous to avoid `memory whole` problems
         scaled_grads = tuple(
-            # pyre-fixme[16]: `tuple` has no attribute `contiguous`.
             layer_grad.contiguous().view(n_steps, -1)
-            # pyre-fixme[16]: `tuple` has no attribute `device`.
             * torch.tensor(step_sizes).view(n_steps, 1).to(layer_grad.device)
             for layer_grad in layer_gradients
         )
@@ -317,8 +314,7 @@ def _attribute(
                 scaled_grad,
                 n_steps,
                 inputs[0].shape[0],
-                # pyre-fixme[16]: `tuple` has no attribute `shape`.
-                layer_grad.shape[1:],
+                tuple(layer_grad.shape[1:]),
             )
             for scaled_grad, layer_grad in zip(scaled_grads, layer_gradients)
         )