diff --git a/specs/core/0_beacon-chain.md b/specs/core/0_beacon-chain.md
index c7103b79e..7167b93a6 100644
--- a/specs/core/0_beacon-chain.md
+++ b/specs/core/0_beacon-chain.md
@@ -697,7 +697,7 @@ def get_active_validator_indices(validators: List[Validator], epoch: EpochNumber
 ### `get_permuted_index`
 
 ```python
-def get_permuted_index(index: int, list_size: int, seed: Bytes32, round_count: int=90) -> List[int]:
+def get_permuted_index(index: int, list_size: int, seed: Bytes32, round_count: int=90) -> int:
     """
     Return `p(index)` in a pseudorandom permutation `p` of `0...list_size-1` with ``seed`` as entropy.