diff --git a/eth2/beacon/helpers.py b/eth2/beacon/helpers.py
index 4a336bc577..24111c3f61 100644
--- a/eth2/beacon/helpers.py
+++ b/eth2/beacon/helpers.py
@@ -633,9 +633,10 @@ def verify_bitfield(bitfield: bytes, committee_size: int) -> bool:
     if len(bitfield) != get_bitfield_length(committee_size):
         return False
 
-    for i in range(committee_size + 1, committee_size - committee_size % 8 + 8):
-        if has_voted(bitfield, i):
-            return False
+    if committee_size % 8 != 0:
+        for i in range(committee_size, committee_size - committee_size % 8 + 8):
+            if has_voted(bitfield, i):
+                return False
 
     return True
 
diff --git a/eth2/beacon/types/validator_records.py b/eth2/beacon/types/validator_records.py
index d57c8ab6e2..26ac330e09 100644
--- a/eth2/beacon/types/validator_records.py
+++ b/eth2/beacon/types/validator_records.py
@@ -14,9 +14,8 @@
     FAR_FUTURE_EPOCH,
 )
 from eth2.beacon.typing import (
-    EpochNumber,
     BLSPubkey,
-    SlotNumber,
+    EpochNumber,
 )