diff --git a/src/transformers/models/longformer/modeling_longformer.py b/src/transformers/models/longformer/modeling_longformer.py
index 9ca1d9a182e7..aea9f4a90250 100755
--- a/src/transformers/models/longformer/modeling_longformer.py
+++ b/src/transformers/models/longformer/modeling_longformer.py
@@ -814,7 +814,7 @@ def _sliding_chunks_query_key_matmul(self, query: torch.Tensor, key: torch.Tenso
         # matrix multiplication
         # bcxd: batch_size * num_heads x chunks x 2window_overlap x head_dim
         # bcyd: batch_size * num_heads x chunks x 2window_overlap x head_dim
-        # bcxy: batch_size * num_heads x chunks x 2window_overlap x window_overlap
+        # bcxy: batch_size * num_heads x chunks x 2window_overlap x 2window_overlap
         diagonal_chunked_attention_scores = torch.einsum("bcxd,bcyd->bcxy", (query, key))  # multiply
 
         # convert diagonals into columns