diff --git a/specs/core/0_beacon-chain.md b/specs/core/0_beacon-chain.md
index ce2472ace..03786a560 100644
--- a/specs/core/0_beacon-chain.md
+++ b/specs/core/0_beacon-chain.md
@@ -1057,7 +1057,7 @@ def is_double_vote(attestation_data_1: AttestationData,
 
 ```python
 def is_surround_vote(attestation_data_1: AttestationData,
-                     attestation_data_2: AttestationData) -> bool
+                     attestation_data_2: AttestationData) -> bool:
     """
     Assumes ``attestation_data_1`` is distinct from ``attestation_data_2``.
     Returns True if the provided ``AttestationData`` are slashable
@@ -1067,7 +1067,7 @@ def is_surround_vote(attestation_data_1: AttestationData,
     """
     return (
         (attestation_data_1.justified_slot < attestation_data_2.justified_slot) and
-        (attestat_data_2.justified_slot + 1 == attestation_data_2.slot) and
+        (attestation_data_2.justified_slot + 1 == attestation_data_2.slot) and
         (attestation_data_2.slot < attestation_data_1.slot)
     )
 ```