diff --git a/src/ethereum_test_fixtures/blockchain.py b/src/ethereum_test_fixtures/blockchain.py
index 3a00484eca..e14287145a 100644
--- a/src/ethereum_test_fixtures/blockchain.py
+++ b/src/ethereum_test_fixtures/blockchain.py
@@ -229,7 +229,7 @@ def from_fixture_header(
 
 EngineNewPayloadV1Parameters = Tuple[FixtureExecutionPayload]
 EngineNewPayloadV3Parameters = Tuple[FixtureExecutionPayload, List[Hash], Hash]
-EngineNewPayloadV4Parameters = Tuple[FixtureExecutionPayload, List[Hash], Hash, List[Bytes]]
+EngineNewPayloadV4Parameters = Tuple[FixtureExecutionPayload, List[Hash], Hash, List[Bytes], HexNumber]
 
 # Important: We check EngineNewPayloadV3Parameters first as it has more fields, and pydantic
 # has a weird behavior when the smaller tuple is checked first.
@@ -291,32 +291,34 @@ def from_fixture_header(
             transactions=transactions,
             withdrawals=withdrawals,
         )
-        params: EngineNewPayloadParameters
-        if (
-            fork.engine_new_payload_requests(header.number, header.timestamp)
-            and requests is not None
-        ):
-            parent_beacon_block_root = header.parent_beacon_block_root
-            assert parent_beacon_block_root is not None
-            params = (
-                execution_payload,
-                Transaction.list_blob_versioned_hashes(transactions),
-                parent_beacon_block_root,
-                requests,
-            )
-        elif fork.engine_new_payload_blob_hashes(header.number, header.timestamp):
-            parent_beacon_block_root = header.parent_beacon_block_root
-            assert parent_beacon_block_root is not None
-            params = (
-                execution_payload,
-                Transaction.list_blob_versioned_hashes(transactions),
-                parent_beacon_block_root,
-            )
-        else:
-            params = (execution_payload,)
 
+        params: List[Any] = [execution_payload]
+        if fork.engine_new_payload_blob_hashes(header.number, header.timestamp):
+            blob_hashes = Transaction.list_blob_versioned_hashes(transactions)
+            if blob_hashes is None:
+                raise ValueError(f"Blob hashes are required for ${fork}.")
+            params.append(blob_hashes)
+
+        if fork.engine_new_payload_beacon_root(header.number, header.timestamp):
+            parent_beacon_block_root = header.parent_beacon_block_root
+            if parent_beacon_block_root is None:
+                raise ValueError(f"Parent beacon block root is required for ${fork}.")
+            params.append(parent_beacon_block_root)
+
+        if fork.engine_new_payload_requests(header.number, header.timestamp):
+            if requests is None:
+                raise ValueError(f"Requests are required for ${fork}.")
+            params.append(requests)
+
+        if fork.engine_new_payload_target_blob_count(header.number, header.timestamp):
+            target_blob_count = header.target_blob_count
+            if target_blob_count is None:
+                raise ValueError(f"Target blob count is required for ${fork}.")
+            params.append(target_blob_count)
+
+        payload_params: EngineNewPayloadParameters = tuple(params)
         new_payload = cls(
-            params=params,
+            params=payload_params,
             new_payload_version=new_payload_version,
             forkchoice_updated_version=forkchoice_updated_version,
             **kwargs,
diff --git a/src/ethereum_test_forks/base_fork.py b/src/ethereum_test_forks/base_fork.py
index c19d6141c2..c2d5b6f711 100644
--- a/src/ethereum_test_forks/base_fork.py
+++ b/src/ethereum_test_forks/base_fork.py
@@ -281,7 +281,15 @@ def engine_new_payload_beacon_root(cls, block_number: int = 0, timestamp: int =
     @abstractmethod
     def engine_new_payload_requests(cls, block_number: int = 0, timestamp: int = 0) -> bool:
         """
-        Returns true if the engine api version requires new payload calls to include requests.
+        returns true if the engine api version requires new payload calls to include requests.
+        """
+        pass
+
+    @classmethod
+    @abstractmethod
+    def engine_new_payload_target_blob_count(cls, block_number: int = 0, timestamp: int = 0) -> bool:
+        """
+        returns true if the engine api version requires new payload calls to include target blob count.
         """
         pass
 
diff --git a/src/ethereum_test_forks/forks/forks.py b/src/ethereum_test_forks/forks/forks.py
index 67599a448c..40f36d96ab 100644
--- a/src/ethereum_test_forks/forks/forks.py
+++ b/src/ethereum_test_forks/forks/forks.py
@@ -961,9 +961,9 @@ def engine_new_payload_requests(cls, block_number: int = 0, timestamp: int = 0)
         return True
 
     @classmethod
-    def engine_new_payload_blob_hashes(cls, block_number: int = 0, timestamp: int = 0) -> bool:
+    def engine_new_payload_target_blob_count(cls, block_number: int = 0, timestamp: int = 0) -> bool:
         """
-        Starting at Prague, new payload directives must contain requests as parameter.
+        Starting at Prague, new payloads include the target blob count as a parameter.
         """
         return True