diff --git a/alibi/explainers/integrated_gradients.py b/alibi/explainers/integrated_gradients.py
index d2726a8ca..96953da7f 100644
--- a/alibi/explainers/integrated_gradients.py
+++ b/alibi/explainers/integrated_gradients.py
@@ -400,6 +400,11 @@ def _gradients_input(model: Union[tf.keras.models.Model],
 
     grads = tape.gradient(preds, x)
 
+    # If certain inputs don't impact the target, the gradient is None, but we need to return a tensor
+    if isinstance(x, list):
+        for idx, grad in enumerate(grads):
+            if grad is None:
+                grads[idx] = tf.convert_to_tensor(np.zeros(x[idx].shape), dtype=x[idx].dtype)
     return grads
 
 
@@ -497,7 +502,11 @@ def wrapper(*args, **kwargs):
         grads = tape.gradient(preds, layer.inp)
     else:
         grads = tape.gradient(preds, layer.result)
-
+    # If certain inputs don't impact the target, the gradient is None, but we need to return a tensor
+    if isinstance(x, list):
+        for idx, grad in enumerate(grads):
+            if grad is None:
+                grads[idx] = tf.convert_to_tensor(np.zeros(x[idx].shape), dtype=x[idx].dtype)
     delattr(layer, 'inp')
     delattr(layer, 'result')
     layer.call = orig_call