diff --git a/comet/encoders/bert.py b/comet/encoders/bert.py
index 753dc70..d6b7992 100644
--- a/comet/encoders/bert.py
+++ b/comet/encoders/bert.py
@@ -168,15 +168,24 @@ def forward(
             Dict[str, torch.Tensor]: dictionary with 'sentemb', 'wordemb', 'all_layers'
                 and 'attention_mask'.
         """
-        last_hidden_states, pooler_output, all_layers = self.model(
+        output = self.model(
             input_ids=input_ids,
             token_type_ids=token_type_ids,
             attention_mask=attention_mask,
             output_hidden_states=True,
             return_dict=False,
         )
+        # Handle both transformers 4.x (3 values) and 5.x (2 values when add_pooling_layer=False)
+        if len(output) == 2:
+            last_hidden_states, all_layers = output
+            # Use CLS token as sentence embedding when no pooler output
+            sentemb = last_hidden_states[:, 0, :]
+        else:
+            last_hidden_states, pooler_output, all_layers = output
+            # Use pooler output if available, otherwise use CLS token
+            sentemb = pooler_output if pooler_output is not None else last_hidden_states[:, 0, :]
         return {
-            "sentemb": pooler_output,
+            "sentemb": sentemb,
             "wordemb": last_hidden_states,
             "all_layers": all_layers,
             "attention_mask": attention_mask,
diff --git a/comet/encoders/xlmr.py b/comet/encoders/xlmr.py
index 13cc15a..5ab76c2 100644
--- a/comet/encoders/xlmr.py
+++ b/comet/encoders/xlmr.py
@@ -92,12 +92,17 @@ def from_pretrained(
     def forward(
         self, input_ids: torch.Tensor, attention_mask: torch.Tensor, **kwargs
     ) -> Dict[str, torch.Tensor]:
-        last_hidden_states, _, all_layers = self.model(
+        output = self.model(
             input_ids=input_ids,
             attention_mask=attention_mask,
             output_hidden_states=True,
             return_dict=False,
         )
+        # Handle both transformers 4.x (3 values) and 5.x (2 values when add_pooling_layer=False)
+        if len(output) == 2:
+            last_hidden_states, all_layers = output
+        else:
+            last_hidden_states, _, all_layers = output
         return {
             "sentemb": last_hidden_states[:, 0, :],
             "wordemb": last_hidden_states,
diff --git a/pyproject.toml b/pyproject.toml
index 214a48c..d98e997 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -39,7 +39,7 @@ comet-mbr = 'comet.cli.mbr:mbr_command'
 python = "^3.8.0"
 sentencepiece = "^0.2.0"
 pandas = ">=1.4.1"
-transformers = "^4.17"
+transformers = ">=4.17"
 pytorch-lightning = "^2.0.0"
 jsonargparse = "3.13.1"
 torch = ">=1.6.0"
@@ -48,7 +48,7 @@ torchmetrics = "^0.10.2"
 sacrebleu = "^2.0.0"
 scipy = "^1.5.4"
 entmax = "^1.1"
-huggingface-hub = ">=0.19.3,<1.0"
+huggingface-hub = ">=0.19.3"
 protobuf = "^4.24.4"
 
 [tool.poetry.dev-dependencies]