diff --git a/src/ethereum/prague/fork.py b/src/ethereum/prague/fork.py
index 419d35c1d2..33db13710c 100644
--- a/src/ethereum/prague/fork.py
+++ b/src/ethereum/prague/fork.py
@@ -45,12 +45,12 @@
     state_root,
 )
 from .transactions import (
+    FLOOR_CALLDATA_COST,
+    STANDARD_CALLDATA_TOKEN_COST,
     TX_ACCESS_LIST_ADDRESS_COST,
     TX_ACCESS_LIST_STORAGE_KEY_COST,
     TX_BASE_COST,
     TX_CREATE_COST,
-    STANDARD_CALLDATA_TOKEN_COST,
-    FLOOR_CALLDATA_COST,
     AccessListTransaction,
     BlobTransaction,
     FeeMarketTransaction,
@@ -922,11 +922,11 @@ def process_transaction(
     effective_gas_fee = tx.gas * env.gas_price
 
     intrinsic_gas, tokens_in_calldata = calculate_intrinsic_cost(tx)
-    
+
     floor = Uint(tokens_in_calldata * FLOOR_CALLDATA_COST + TX_BASE_COST)
     if floor > tx.gas:
         raise InvalidBlock
-    
+
     gas = tx.gas - intrinsic_gas
     increment_nonce(env.state, sender)
 
@@ -970,17 +970,18 @@ def process_transaction(
 
     output = process_message_call(message, env)
 
-    # For EIP-7623 gas_used includes the intrinsic costs with the floor price for calldata
+    # For EIP-7623 gas_used includes the intrinsic costs with the floor price
+    # for calldata.
     gas_used = tx.gas - output.gas_left
-    
+
     # EIP-7623 floor price (note: no EVM costs)
-    
+
     # Transactions with less gas used than the floor pay at the floor cost.
     if gas_used < floor:
         gas_used = floor
-    
+
     output.gas_left = tx.gas - gas_used
-     
+
     gas_refund = min(gas_used // 5, output.refund_counter)
     gas_refund_amount = (output.gas_left + gas_refund) * env.gas_price
 
@@ -1044,13 +1045,13 @@ def calculate_intrinsic_cost(tx: Transaction) -> Tuple[Uint, Uint]:
     """
     data_cost = 0
 
-    zerobytes = 0
+    zero_bytes = 0
     for byte in tx.data:
         if byte == 0:
-            zerobytes += 1
+            zero_bytes += 1
+
+    tokens_in_calldata = zero_bytes + (len(tx.data) - zero_bytes) * 4
 
-    tokens_in_calldata = zerobytes + (len(tx.data) - zerobytes) * 4
-    
     data_cost = tokens_in_calldata * STANDARD_CALLDATA_TOKEN_COST
 
     if tx.to == Bytes0(b""):
@@ -1076,9 +1077,17 @@ def calculate_intrinsic_cost(tx: Transaction) -> Tuple[Uint, Uint]:
     if isinstance(tx, SetCodeTransaction):
         auth_cost += PER_EMPTY_ACCOUNT_COST * len(tx.authorizations)
 
-    return Uint(TX_BASE_COST +
-                data_cost +
-                create_cost + access_list_cost + auth_cost), tokens_in_calldata
+    return (
+        Uint(
+            TX_BASE_COST
+            + data_cost
+            + create_cost
+            + access_list_cost
+            + auth_cost
+        ),
+        Uint(tokens_in_calldata),
+    )
+
 
 def recover_sender(chain_id: U64, tx: Transaction) -> Address:
     """
diff --git a/whitelist.txt b/whitelist.txt
index f309ebbb8f..ccc117c05d 100644
--- a/whitelist.txt
+++ b/whitelist.txt
@@ -12,12 +12,14 @@ Bytes64
 Bytes8
 Bytes256
 Bytes0
+calldata
 copyreg
 copytree
 coinbase
 coincurve
 crypto
 E501
+EIP
 encodings
 endian
 eth
@@ -459,4 +461,4 @@ exponentiate
 monomial
 impl
 
-eoa
\ No newline at end of file
+eoa