diff --git a/presets/mainnet/merge.yaml b/presets/mainnet/merge.yaml
index 97f07c7f0..66f7abe28 100644
--- a/presets/mainnet/merge.yaml
+++ b/presets/mainnet/merge.yaml
@@ -1,3 +1,16 @@
 # Mainnet preset - The Merge
 
-# No presets here.
+# Execution
+# ---------------------------------------------------------------
+# 2**20 (= 1,048,576)
+MAX_BYTES_PER_TRANSACTION: 1048576
+# 2**14 (= 16,384)
+MAX_TRANSACTIONS_PER_PAYLOAD: 16384
+# 2**8 (= 256)
+BYTES_PER_LOGS_BLOOM: 256
+# 2**10 (= 1,024)
+GAS_LIMIT_DENOMINATOR: 1024
+# 5,000
+MIN_GAS_LIMIT: 5000
+# 2**5 (= 32)
+MAX_EXTRA_DATA_BYTES: 32
diff --git a/presets/minimal/merge.yaml b/presets/minimal/merge.yaml
index 88aa86c09..d9b5640dd 100644
--- a/presets/minimal/merge.yaml
+++ b/presets/minimal/merge.yaml
@@ -1,3 +1,16 @@
 # Minimal preset - The Merge
 
-# No presets here.
+# Execution
+# ---------------------------------------------------------------
+# 2**20 (= 1,048,576)
+MAX_BYTES_PER_TRANSACTION: 1048576
+# 2**14 (= 16,384)
+MAX_TRANSACTIONS_PER_PAYLOAD: 16384
+# 2**8 (= 256)
+BYTES_PER_LOGS_BLOOM: 256
+# 2**10 (= 1,024)
+GAS_LIMIT_DENOMINATOR: 1024
+# 5,000
+MIN_GAS_LIMIT: 5000
+# 2**5 (= 32)
+MAX_EXTRA_DATA_BYTES: 32
diff --git a/setup.py b/setup.py
index e414d2721..4524df2ca 100644
--- a/setup.py
+++ b/setup.py
@@ -497,7 +497,7 @@ class MergeSpecBuilder(AltairSpecBuilder):
         return super().imports(preset_name) + f'''
 from typing import Protocol
 from eth2spec.altair import {preset_name} as altair
-from eth2spec.utils.ssz.ssz_typing import Bytes8, Bytes20, ByteList, ByteVector, uint256, Union
+from eth2spec.utils.ssz.ssz_typing import Bytes8, Bytes20, ByteList, ByteVector, uint256
 '''
 
     @classmethod
@@ -543,7 +543,7 @@ EXECUTION_ENGINE = NoopExecutionEngine()"""
     @classmethod
     def hardcoded_custom_type_dep_constants(cls) -> str:
         constants = {
-            'MAX_BYTES_PER_OPAQUE_TRANSACTION': 'uint64(2**20)',
+            'MAX_BYTES_PER_TRANSACTION': 'uint64(2**20)',
         }
         return {**super().hardcoded_custom_type_dep_constants(), **constants}
 
diff --git a/specs/merge/beacon-chain.md b/specs/merge/beacon-chain.md
index 2e1fd88fb..8fafb0720 100644
--- a/specs/merge/beacon-chain.md
+++ b/specs/merge/beacon-chain.md
@@ -50,8 +50,7 @@ This patch adds transaction execution to the beacon chain as part of the Merge f
 
 | Name | SSZ equivalent | Description |
 | - | - | - |
-| `OpaqueTransaction` | `ByteList[MAX_BYTES_PER_OPAQUE_TRANSACTION]` | a [typed transaction envelope](https://eips.ethereum.org/EIPS/eip-2718#opaque-byte-array-rather-than-an-rlp-array) structured as `TransactionType \|\| TransactionPayload` |
-| `Transaction` | `Union[OpaqueTransaction]` | a transaction |
+| `Transaction` | `ByteList[MAX_BYTES_PER_TRANSACTION]` | either a [typed transaction envelope](https://eips.ethereum.org/EIPS/eip-2718#opaque-byte-array-rather-than-an-rlp-array) or a legacy transaction|
 | `ExecutionAddress` | `Bytes20` | Address of account on the execution layer |
 
 ## Constants
@@ -60,7 +59,7 @@ This patch adds transaction execution to the beacon chain as part of the Merge f
 
 | Name | Value |
 | - | - |
-| `MAX_BYTES_PER_OPAQUE_TRANSACTION` | `uint64(2**20)` (= 1,048,576) |
+| `MAX_BYTES_PER_TRANSACTION` | `uint64(2**20)` (= 1,048,576) |
 | `MAX_TRANSACTIONS_PER_PAYLOAD` | `uint64(2**14)` (= 16,384) |
 | `BYTES_PER_LOGS_BLOOM` | `uint64(2**8)` (= 256) |
 | `GAS_LIMIT_DENOMINATOR` | `uint64(2**10)` (= 1,024) |