diff --git a/specs/eip4844/polynomial-commitments.md b/specs/eip4844/polynomial-commitments.md
index b18122b037..c02f9cb8b5 100644
--- a/specs/eip4844/polynomial-commitments.md
+++ b/specs/eip4844/polynomial-commitments.md
@@ -166,7 +166,7 @@ def blob_to_polynomial(blob: Blob) -> Polynomial:
 
 ```python
 def compute_challenges(polynomials: Sequence[Polynomial],
-                       commitments: Sequence[KZGCommitment]) -> BLSFieldElement:
+                       commitments: Sequence[KZGCommitment]) -> Tuple[Sequence[BLSFieldElement], BLSFieldElement]:
     """
     Return the Fiat-Shamir challenges required by the rest of the protocol.
     The Fiat-Shamir logic works as per the following pseudocode: