diff --git a/specs/core/0_beacon-chain.md b/specs/core/0_beacon-chain.md
index 7a79dde01..a0c3d85c0 100644
--- a/specs/core/0_beacon-chain.md
+++ b/specs/core/0_beacon-chain.md
@@ -1121,7 +1121,7 @@ def get_genesis_beacon_state(eth1_block_hash: Hash, eth1_timestamp: int, deposit
 
     # Process activations
     for index, validator in enumerate(state.validators):
-        if balances[index] >= MAX_EFFECTIVE_BALANCE:
+        if state.balances[index] >= MAX_EFFECTIVE_BALANCE:
             validator.activation_eligibility_epoch = GENESIS_EPOCH
             validator.activation_epoch = GENESIS_EPOCH
     assert len(get_active_validator_indices(state, GENESIS_EPOCH)) >= MIN_MIN_GENESIS_ACTIVE_VALIDATOR_COUNT