diff --git a/specs/validator/0_beacon-chain-validator.md b/specs/validator/0_beacon-chain-validator.md
index 9e4fa7960b..0940d592a6 100644
--- a/specs/validator/0_beacon-chain-validator.md
+++ b/specs/validator/0_beacon-chain-validator.md
@@ -148,8 +148,9 @@ def get_committee_assignment(
 
     committees_per_slot = get_epoch_committee_count(state, epoch) // SLOTS_PER_EPOCH
     epoch_start_slot = get_epoch_start_slot(epoch)
-    for slot in range(epoch_start_slot, epoch_start_slot + SLOTS_PER_EPOCH):
-        slot_start_shard = get_epoch_start_shard(state, epoch) + committees_per_slot * (slot % SLOTS_PER_EPOCH)
+    for slot in range(epoch_start_slot, epoch_start_slot + SLOTS_PER_EPOCH)
+        offset = committees_per_slot * (slot % SLOTS_PER_EPOCH)
+        slot_start_shard = (get_epoch_start_shard(state, epoch) + offset) % SHARD_COUNT
         for i in range(committees_per_slot):
             shard = (slot_start_shard + i) % SHARD_COUNT
             committee = get_crosslink_committee(state, epoch, shard)