diff --git a/src/transformers/models/mamba2/modeling_mamba2.py b/src/transformers/models/mamba2/modeling_mamba2.py
index 7b414ff9570..19d53437130 100644
--- a/src/transformers/models/mamba2/modeling_mamba2.py
+++ b/src/transformers/models/mamba2/modeling_mamba2.py
@@ -510,7 +510,7 @@ class Mamba2Mixer(nn.Module):
             C = C.reshape(batch_size, seq_len, -1, self.ssm_state_size).float()
             B = B.repeat(1, 1, self.num_heads // self.n_groups, 1)
             C = C.repeat(1, 1, self.num_heads // self.n_groups, 1)
-            pad_size = self.chunk_size - (seq_len % self.chunk_size)
+            pad_size = (self.chunk_size - seq_len % self.chunk_size) % self.chunk_size
 
             D_residual = self.D[..., None] * pad_tensor_by_size(hidden_states, pad_size)
 
diff --git a/tests/models/mamba2/test_modeling_mamba2.py b/tests/models/mamba2/test_modeling_mamba2.py
index 55c18abe6b9..f19358a22f4 100644
--- a/tests/models/mamba2/test_modeling_mamba2.py
+++ b/tests/models/mamba2/test_modeling_mamba2.py
@@ -291,6 +291,7 @@ class Mamba2IntegrationTest(unittest.TestCase):
         self.tokenizer = AutoTokenizer.from_pretrained(self.model_id, from_slow=True, legacy=False)
         self.prompt = ("[INST]Write a hello world program in C++.",)
 
+    @require_read_token
     @parameterized.expand(
         [
             (torch_device,),
@@ -319,6 +320,7 @@ class Mamba2IntegrationTest(unittest.TestCase):
         ground_truth_sentence = """<s>[INST]Write a hello world program in C++.[/INST] Sure, here is a simple "Hello, World!" program in C++:\n\n```cpp\n#include <iostream>\n\n"""
         self.assertEqual(output_sentence, ground_truth_sentence)
 
+    @require_read_token
     @slow
     @require_torch_gpu
     def test_batched_equivalence_with_cache(self):
@@ -349,6 +351,7 @@ class Mamba2IntegrationTest(unittest.TestCase):
             individual_output = tokenizer.batch_decode(individual_gen, skip_special_tokens=True)[0]
             self.assertEqual(individual_output[:100], batched_output[index_gen][:100])
 
+    @require_read_token
     @slow
     @require_torch_gpu
     def test_batched_equivalence_without_cache(self):