diff --git a/beacon_chain/spec/datatypes/merge.nim b/beacon_chain/spec/datatypes/merge.nim
index b8f2fcf2d..83012c38c 100644
--- a/beacon_chain/spec/datatypes/merge.nim
+++ b/beacon_chain/spec/datatypes/merge.nim
@@ -24,6 +24,7 @@ const
   BYTES_PER_LOGS_BLOOM = 256
   GAS_LIMIT_DENOMINATOR = 1024
   MIN_GAS_LIMIT = 5000
+  MAX_EXTRA_DATA_BYTES = 32
 
 type
   # https://github.com/ethereum/consensus-specs/blob/v1.1.0-beta.4/specs/merge/beacon-chain.md#custom-types
@@ -48,6 +49,7 @@ type
     gas_limit*: uint64
     gas_used*: uint64
     timestamp*: uint64
+    extra_data*: List[byte, MAX_EXTRA_DATA_BYTES]
     base_fee_per_gas*: Eth2Digest  # base fee introduced in EIP-1559, little-endian serialized
 
     # Extra payload fields
@@ -66,6 +68,7 @@ type
     gas_limit*: uint64
     gas_used*: uint64
     timestamp*: uint64
+    extra_data*: List[byte, MAX_EXTRA_DATA_BYTES]
     base_fee_per_gas*: Eth2Digest  # base fee introduced in EIP-1559, little-endian serialized
 
     # Extra payload fields
diff --git a/tests/official/fixtures_utils.nim b/tests/official/fixtures_utils.nim
index 59a4bbdc6..b8cfa1a2c 100644
--- a/tests/official/fixtures_utils.nim
+++ b/tests/official/fixtures_utils.nim
@@ -39,7 +39,7 @@ type
 const
   FixturesDir* =
     currentSourcePath.rsplit(DirSep, 1)[0] / ".." / ".." / "vendor" / "nim-eth2-scenarios"
-  SszTestsDir* = FixturesDir / "tests-v1.1.0-beta.4"
+  SszTestsDir* = FixturesDir / "tests-v1.1.0-beta.5"
   MaxObjectSize* = 3_000_000
 
 proc parseTest*(path: string, Format: typedesc[Json], T: typedesc): T =
diff --git a/vendor/nim-eth2-scenarios b/vendor/nim-eth2-scenarios
index 927811da3..9317581ea 160000
--- a/vendor/nim-eth2-scenarios
+++ b/vendor/nim-eth2-scenarios
@@ -1 +1 @@
-Subproject commit 927811da3ecb3f7c5ca0c74533e78ee4aec147e9
+Subproject commit 9317581ea9efce38da0b3023dccb21b23c2178e5