diff --git a/docs/CHANGELOG.md b/docs/CHANGELOG.md
index 65c4d1ce38..c309c88ea1 100644
--- a/docs/CHANGELOG.md
+++ b/docs/CHANGELOG.md
@@ -8,6 +8,8 @@ Test fixtures for use by clients are available for each release on the [Github r
 
 ### 🧪 Test Cases
 
+- 🐞 Fix beacon root contract deployment tests so the account in the pre-alloc is not empty ([#425](https://github.com/ethereum/execution-spec-tests/pull/425)).
+
 ### 🛠️ Framework
 
 - ✨ Add Prague to forks ([#419](https://github.com/ethereum/execution-spec-tests/pull/419)).
diff --git a/src/ethereum_test_tools/common/types.py b/src/ethereum_test_tools/common/types.py
index 113ed8fe22..49523a1c7b 100644
--- a/src/ethereum_test_tools/common/types.py
+++ b/src/ethereum_test_tools/common/types.py
@@ -519,6 +519,12 @@ def check_alloc(self: "Account", address: Address, alloc: dict):
             actual_storage = Storage(alloc["storage"]) if "storage" in alloc else Storage({})
             expected_storage.must_be_equal(address=address, other=actual_storage)
 
+    def has_empty_code(self: "Account") -> bool:
+        """
+        Returns true if an account has no bytecode.
+        """
+        return not self.code or Bytes(self.code) == b""
+
     def is_empty(self: "Account") -> bool:
         """
         Returns true if an account deemed empty.
@@ -526,7 +532,7 @@ def is_empty(self: "Account") -> bool:
         return (
             (self.nonce == 0 or self.nonce is None)
             and (self.balance == 0 or self.balance is None)
-            and (not self.code and self.code is None)
+            and self.has_empty_code()
             and (not self.storage or self.storage == {} or self.storage is None)
         )
 
@@ -580,9 +586,7 @@ def __init__(self, d: Mapping[FixedSizeBytesConvertible, Account | Dict] = {}):
         for address, account in d.items():
             address = Address(address)
             assert address not in self, f"Duplicate address in alloc: {address}"
-            account = Account.from_dict(account)
-            assert not account.is_empty(), f"Empty account: {account} for address: {address}"
-            self[address] = account
+            self[address] = Account.from_dict(account)
 
     @classmethod
     def merge(cls, alloc_1: "Alloc", alloc_2: "Alloc") -> "Alloc":
@@ -592,10 +596,21 @@ def merge(cls, alloc_1: "Alloc", alloc_2: "Alloc") -> "Alloc":
         merged = alloc_1.copy()
 
         for address, other_account in alloc_2.items():
-            merged[address] = Account.merge(merged.get(address, None), other_account)
+            merged_account = Account.merge(merged.get(address, None), other_account)
+            if merged_account.is_empty():
+                if address in merged:
+                    merged.pop(address, None)
+            else:
+                merged[address] = merged_account
 
         return Alloc(merged)
 
+    def empty_accounts(self) -> List[Address]:
+        """
+        Returns a list of addresses of empty accounts.
+        """
+        return [address for address, account in self.items() if account.is_empty()]
+
     def __json__(self, encoder: JSONEncoder) -> Mapping[str, Any]:
         """
         Returns the JSON representation of the allocation.
diff --git a/src/ethereum_test_tools/spec/blockchain/blockchain_test.py b/src/ethereum_test_tools/spec/blockchain/blockchain_test.py
index e5e1b5d20e..cef192ad7f 100644
--- a/src/ethereum_test_tools/spec/blockchain/blockchain_test.py
+++ b/src/ethereum_test_tools/spec/blockchain/blockchain_test.py
@@ -1,6 +1,7 @@
 """
 Ethereum blockchain test spec definition and filler.
 """
+
 from copy import copy
 from dataclasses import dataclass, field, replace
 from pprint import pprint
@@ -133,12 +134,16 @@ def make_genesis(
         if env.beacon_root is not None:
             assert Hash(env.beacon_root) == Hash(0), "beacon_root must be empty at genesis"
 
-        pre_alloc = Alloc(
-            fork.pre_allocation(block_number=0, timestamp=Number(env.timestamp)),
+        pre_alloc = Alloc.merge(
+            Alloc(
+                fork.pre_allocation(block_number=0, timestamp=Number(env.timestamp)),
+            ),
+            Alloc(self.pre),
         )
-
+        if empty_accounts := pre_alloc.empty_accounts():
+            raise Exception(f"Empty accounts in pre state: {empty_accounts}")
         new_alloc, state_root = t8n.calc_state_root(
-            alloc=to_json(Alloc.merge(pre_alloc, Alloc(self.pre))),
+            alloc=to_json(pre_alloc),
             fork=fork,
             debug_output_path=self.get_next_transition_tool_output_path(),
         )
diff --git a/src/ethereum_test_tools/spec/state/state_test.py b/src/ethereum_test_tools/spec/state/state_test.py
index f08814fff5..fcc0dc22eb 100644
--- a/src/ethereum_test_tools/spec/state/state_test.py
+++ b/src/ethereum_test_tools/spec/state/state_test.py
@@ -1,6 +1,7 @@
 """
 Ethereum state test spec definition and filler.
 """
+
 from copy import copy
 from dataclasses import dataclass
 from typing import Callable, Generator, List, Mapping, Optional, Type
@@ -133,6 +134,8 @@ def make_state_test_fixture(
             ),
             Alloc(self.pre),
         )
+        if empty_accounts := pre_alloc.empty_accounts():
+            raise Exception(f"Empty accounts in pre state: {empty_accounts}")
         transition_tool_name = fork.transition_tool_name(
             block_number=Number(self.env.number),
             timestamp=Number(self.env.timestamp),