diff --git a/inseq/attr/feat/internals_attribution.py b/inseq/attr/feat/internals_attribution.py
index 003c186..f3f0479 100644
--- a/inseq/attr/feat/internals_attribution.py
+++ b/inseq/attr/feat/internals_attribution.py
@@ -16,7 +16,6 @@
 import logging
 from typing import Any, Optional
 
-import torch
 from captum._utils.typing import TensorOrTupleOfTensorsGeneric
 
 from ...data import MultiDimensionalFeatureAttributionStepOutput
@@ -77,11 +76,6 @@ def attribute(
             # We adopt the format [batch_size, sequence_length, sequence_length, num_layers, num_heads]
             # for consistency with other multi-unit methods (e.g. gradient attribution)
             decoder_self_attentions = decoder_self_attentions.to("cpu").clone().permute(0, 4, 3, 1, 2)
-            decoder_self_attentions = torch.where(
-                decoder_self_attentions == 0,
-                (torch.ones_like(decoder_self_attentions) * float("nan")),
-                decoder_self_attentions,
-            )
             if self.forward_func.is_encoder_decoder:
                 sequence_scores = {}
                 if len(inputs) > 1:
diff --git a/inseq/models/huggingface_model.py b/inseq/models/huggingface_model.py
index 3ea8bc5..bb44f21 100644
--- a/inseq/models/huggingface_model.py
+++ b/inseq/models/huggingface_model.py
@@ -109,14 +109,23 @@ def __init__(
             self.tokenizer = tokenizer
         else:
             self.tokenizer = AutoTokenizer.from_pretrained(tokenizer, **tokenizer_kwargs)
-        if self.model.config.pad_token_id is not None:
-            self.pad_token = self._convert_ids_to_tokens(self.model.config.pad_token_id, skip_special_tokens=False)
+        self.eos_token_id = getattr(self.model.config, "eos_token_id", None)
+        pad_token_id = self.model.config.pad_token_id
+        if pad_token_id is None:
+            if self.tokenizer.pad_token_id is None:
+                logger.info(f"Setting `pad_token_id` to `eos_token_id`:{self.eos_token_id} for open-end generation.")
+                pad_token_id = self.eos_token_id
+            else:
+                pad_token_id = self.tokenizer.pad_token_id
+        self.pad_token = self._convert_ids_to_tokens(pad_token_id, skip_special_tokens=False)
+        if self.tokenizer.pad_token is None:
             self.tokenizer.pad_token = self.pad_token
+        if self.model.config.pad_token_id is None:
+            self.model.config.pad_token_id = pad_token_id
         self.bos_token_id = getattr(self.model.config, "decoder_start_token_id", None)
         if self.bos_token_id is None:
             self.bos_token_id = self.model.config.bos_token_id
         self.bos_token = self._convert_ids_to_tokens(self.bos_token_id, skip_special_tokens=False)
-        self.eos_token_id = getattr(self.model.config, "eos_token_id", None)
         if self.eos_token_id is None:
             self.eos_token_id = self.tokenizer.pad_token_id
         if self.tokenizer.unk_token_id is None: