diff --git a/docs/CHANGELOG.md b/docs/CHANGELOG.md
index 35270f8ed1..76ddb5c590 100644
--- a/docs/CHANGELOG.md
+++ b/docs/CHANGELOG.md
@@ -40,6 +40,7 @@ Test fixtures for use by clients are available for each release on the [Github r
 - ✨ Add "description" and "url" fields containing test case documentation and a source code permalink to fixtures during `fill` and use them in `consume`-generated Hive test reports ([#579](https://github.com/ethereum/execution-spec-tests/pull/579)).
 - ✨ Add git workflow evmone coverage script for any new lines mentioned in converted_ethereum_tests.txt ([#503](https://github.com/ethereum/execution-spec-tests/pull/503)).
 - ✨ Add a new covariant marker `with_all_contract_creating_tx_types` that allows automatic parametrization of a test with all contract-creating transaction types at the current executing fork ([#602](https://github.com/ethereum/execution-spec-tests/pull/602)).
+- ✨ Enable loading of [ethereum/tests/BlockchainTests](https://github.com/ethereum/tests/tree/develop/BlockchainTests) ([#596](https://github.com/ethereum/execution-spec-tests/pull/596)).
 
 ### 🔧 EVM Tools
 
diff --git a/src/cli/gen_index.py b/src/cli/gen_index.py
index 639befe0ab..eb461db4af 100644
--- a/src/cli/gen_index.py
+++ b/src/cli/gen_index.py
@@ -25,6 +25,18 @@
 
 from .hasher import HashableItem
 
+# TODO: remove when these tests are ported or fixed within ethereum/tests.
+fixtures_to_skip = set(
+    [
+        # These fixtures have invalid fields that we can't load into our pydantic models (bigint).
+        "BlockchainTests/GeneralStateTests/stTransactionTest/ValueOverflowParis.json",
+        "BlockchainTests/InvalidBlocks/bc4895-withdrawals/withdrawalsAmountBounds.json",
+        "BlockchainTests/InvalidBlocks/bc4895-withdrawals/withdrawalsIndexBounds.json",
+        "BlockchainTests/InvalidBlocks/bc4895-withdrawals/withdrawalsValidatorIndexBounds.json",
+        "BlockchainTests/InvalidBlocks/bc4895-withdrawals/withdrawalsAddressBounds.json",
+    ]
+)
+
 
 def count_json_files_exclude_index(start_path: Path) -> int:
     """
@@ -47,6 +59,8 @@ def infer_fixture_format_from_path(file: Path) -> FixtureFormats:
         return FixtureFormats.BLOCKCHAIN_TEST_HIVE
     if "blockchain_tests" in file.parts:
         return FixtureFormats.BLOCKCHAIN_TEST
+    if "BlockchainTests" in file.parts:  # ethereum/tests
+        return FixtureFormats.BLOCKCHAIN_TEST
     if "state_tests" in file.parts:
         return FixtureFormats.STATE_TEST
     return FixtureFormats.UNSET_TEST_FORMAT
@@ -167,6 +181,9 @@ def generate_fixtures_index(
                 continue
             if "blockchain_tests_hive" in file.parts:
                 continue
+            if any(fixture in str(file) for fixture in fixtures_to_skip):
+                rich.print(f"Skipping '{file}'")
+                continue
 
             try:
                 fixture_format = None
diff --git a/src/cli/hasher.py b/src/cli/hasher.py
index e724d57fc5..341606c15b 100644
--- a/src/cli/hasher.py
+++ b/src/cli/hasher.py
@@ -79,13 +79,16 @@ def from_json_file(cls, *, file_path: Path, parents: List[str]) -> "HashableItem
                 raise TypeError(f"Expected dict, got {type(item)} for {key}")
             if "_info" not in item:
                 raise KeyError(f"Expected '_info' in {key}")
-            if "hash" not in item["_info"]:
-                raise KeyError(f"Expected 'hash' in {key}")
-            if not isinstance(item["_info"]["hash"], str):
-                raise TypeError(
-                    f"Expected hash to be a string in {key}, got {type(item['_info']['hash'])}"
-                )
-            item_hash_bytes = bytes.fromhex(item["_info"]["hash"][2:])
+
+            # EEST uses 'hash'; ethereum/tests use 'generatedTestHash'
+            hash_value = item["_info"].get("hash") or item["_info"].get("generatedTestHash")
+            if hash_value is None:
+                raise KeyError(f"Expected 'hash' or 'generatedTestHash' in {key}")
+
+            if not isinstance(hash_value, str):
+                raise TypeError(f"Expected hash to be a string in {key}, got {type(hash_value)}")
+
+            item_hash_bytes = bytes.fromhex(hash_value[2:])
             items[key] = cls(
                 type=HashableItemType.TEST,
                 root=item_hash_bytes,
diff --git a/src/ethereum_test_tools/spec/blockchain/types.py b/src/ethereum_test_tools/spec/blockchain/types.py
index 9b00d6f5c5..41dda76238 100644
--- a/src/ethereum_test_tools/spec/blockchain/types.py
+++ b/src/ethereum_test_tools/spec/blockchain/types.py
@@ -3,7 +3,17 @@
 """
 
 from functools import cached_property
-from typing import Annotated, Any, ClassVar, Dict, List, Literal, get_args, get_type_hints
+from typing import (
+    Annotated,
+    Any,
+    ClassVar,
+    Dict,
+    List,
+    Literal,
+    Optional,
+    get_args,
+    get_type_hints,
+)
 
 from ethereum import rlp as eth_rlp
 from ethereum.base_types import Uint
@@ -636,7 +646,7 @@ class FixtureCommon(BaseFixture):
     fork: str = Field(..., alias="network")
     genesis: FixtureHeader = Field(..., alias="genesisBlockHeader")
     pre: Alloc
-    post_state: Alloc
+    post_state: Optional[Alloc] = Field(None)
 
     def get_fork(self) -> str:
         """
diff --git a/whitelist.txt b/whitelist.txt
index 48880d34e3..17c804ed50 100644
--- a/whitelist.txt
+++ b/whitelist.txt
@@ -19,6 +19,7 @@ basename
 bb
 besu
 bidict
+bigint
 big0
 big1
 blobgasfee