diff --git a/hive_integration/nodocker/engine/cancun/helpers.nim b/hive_integration/nodocker/engine/cancun/helpers.nim
index bafb26efb6..62befc710b 100644
--- a/hive_integration/nodocker/engine/cancun/helpers.nim
+++ b/hive_integration/nodocker/engine/cancun/helpers.nim
@@ -1,5 +1,5 @@
 # Nimbus
-# Copyright (c) 2023-2024 Status Research & Development GmbH
+# Copyright (c) 2023-2025 Status Research & Development GmbH
 # Licensed under either of
 #  * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or
 #    http://www.apache.org/licenses/LICENSE-2.0)
@@ -39,19 +39,27 @@ const
   DATAHASH_START_ADDRESS* = toAddress(0x20000.u256)
   DATAHASH_ADDRESS_COUNT* = 1000
 
-func getMinExcessBlobGasForBlobGasPrice(data_gas_price: uint64, electra: bool): uint64 =
+func getCancunBlobBaseFee*(excessBlobGas: uint64): UInt256 =
+  const blobBaseFeeUpdateFraction = 3338477.u256
+  fakeExponential(
+    MIN_BLOB_GASPRICE.u256,
+    excessBlobGas.u256,
+    blobBaseFeeUpdateFraction
+  )
+
+func getMinExcessBlobGasForBlobGasPrice(data_gas_price: uint64): uint64 =
   var
     current_excess_data_gas = 0'u64
     current_data_gas_price  = 1'u64
 
   while current_data_gas_price < data_gas_price:
     current_excess_data_gas += GAS_PER_BLOB.uint64
-    current_data_gas_price = getBlobBaseFee(current_excess_data_gas, electra).truncate(uint64)
+    current_data_gas_price = getCancunBlobBaseFee(current_excess_data_gas).truncate(uint64)
 
   return current_excess_data_gas
 
-func getMinExcessBlobsForBlobGasPrice*(data_gas_price: uint64, electra: bool): uint64 =
-  return getMinExcessBlobGasForBlobGasPrice(data_gas_price, electra) div GAS_PER_BLOB.uint64
+func getMinExcessBlobsForBlobGasPrice*(data_gas_price: uint64): uint64 =
+  return getMinExcessBlobGasForBlobGasPrice(data_gas_price) div GAS_PER_BLOB.uint64
 
 proc addBlobTransaction*(pool: TestBlobTxPool, tx: PooledTransaction) =
   let txHash = rlpHash(tx)
diff --git a/hive_integration/nodocker/engine/cancun/step_newpayloads.nim b/hive_integration/nodocker/engine/cancun/step_newpayloads.nim
index fe8dace943..e60b4c191e 100644
--- a/hive_integration/nodocker/engine/cancun/step_newpayloads.nim
+++ b/hive_integration/nodocker/engine/cancun/step_newpayloads.nim
@@ -1,5 +1,5 @@
 # Nimbus
-# Copyright (c) 2023-2024 Status Research & Development GmbH
+# Copyright (c) 2023-2025 Status Research & Development GmbH
 # Licensed under either of
 #  * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or
 #    http://www.apache.org/licenses/LICENSE-2.0)
@@ -96,7 +96,7 @@ proc verifyPayload(step: NewPayloads,
 
     var
       totalBlobCount = 0
-      expectedBlobGasPrice = getBlobBaseFee(expectedExcessBlobGas, com.isPragueOrLater(payload.timestamp.EthTime))
+      expectedBlobGasPrice = getCancunBlobBaseFee(expectedExcessBlobGas)
 
     for tx in blobTxsInPayload:
       let blobCount = tx.versionedHashes.len
diff --git a/hive_integration/nodocker/engine/cancun_tests.nim b/hive_integration/nodocker/engine/cancun_tests.nim
index 41e09dbb0d..ed03674c2e 100644
--- a/hive_integration/nodocker/engine/cancun_tests.nim
+++ b/hive_integration/nodocker/engine/cancun_tests.nim
@@ -1,5 +1,5 @@
 # Nimbus
-# Copyright (c) 2023-2024 Status Research & Development GmbH
+# Copyright (c) 2023-2025 Status Research & Development GmbH
 # Licensed under either of
 #  * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or
 #    http://www.apache.org/licenses/LICENSE-2.0)
@@ -41,7 +41,7 @@ import
 
 # Precalculate the first data gas cost increase
 const
-  DATA_GAS_COST_INCREMENT_EXCEED_BLOBS = getMinExcessBlobsForBlobGasPrice(2, false).int
+  DATA_GAS_COST_INCREMENT_EXCEED_BLOBS = getMinExcessBlobsForBlobGasPrice(2).int
   TARGET_BLOBS_PER_BLOCK = int(TARGET_BLOB_GAS_PER_BLOCK div GAS_PER_BLOB)
 
 proc getGenesis(param: NetworkParams) =
diff --git a/nimbus/common/chain_config.nim b/nimbus/common/chain_config.nim
index 05b6cd5712..a4f2b40462 100644
--- a/nimbus/common/chain_config.nim
+++ b/nimbus/common/chain_config.nim
@@ -394,10 +394,18 @@ proc validateChainConfig(conf: ChainConfig): bool =
 proc configureBlobSchedule(conf: ChainConfig) =
   var prevFork = Cancun
   if conf.blobSchedule[Cancun].isNone:
-    conf.blobSchedule[Cancun] = Opt.some(BlobSchedule(target: 3'u64, max: 6'u64))
+    conf.blobSchedule[Cancun] = Opt.some(BlobSchedule(target: 3'u64, max: 6'u64, baseFeeUpdateFraction: 3_338_477'u64))
+  else:
+    if conf.blobSchedule[Cancun].value.baseFeeUpdateFraction == 0:
+      conf.blobSchedule[Cancun].value.baseFeeUpdateFraction = 3_338_477'u64
+
   for fork in Prague..HardFork.high:
     if conf.blobSchedule[fork].isNone:
       conf.blobSchedule[fork] = conf.blobSchedule[prevFork]
+    if conf.blobSchedule[fork].value.baseFeeUpdateFraction == 0:
+      # Set fallback to Cancun's baseFeeUpdateFraction and prevent division by zero
+      warn "baseFeeUpdateFraction not set, fallback to Cancun's", fork=fork
+      conf.blobSchedule[fork].value.baseFeeUpdateFraction = 3_338_477'u64
     prevFork = fork
 
 proc parseGenesis*(data: string): Genesis
@@ -485,9 +493,9 @@ proc parseGenesisAlloc*(data: string, ga: var GenesisAlloc): bool
 
 func defaultBlobSchedule*(): array[Cancun..HardFork.high, Opt[BlobSchedule]] =
   [
-    Cancun: Opt.some(BlobSchedule(target: 3'u64, max: 6'u64)),
-    Prague: Opt.some(BlobSchedule(target: 6'u64, max: 9'u64)),
-    Osaka : Opt.some(BlobSchedule(target: 6'u64, max: 9'u64)),
+    Cancun: Opt.some(BlobSchedule(target: 3'u64, max: 6'u64, baseFeeUpdateFraction: 3_338_477'u64)),
+    Prague: Opt.some(BlobSchedule(target: 6'u64, max: 9'u64, baseFeeUpdateFraction: 5_007_716'u64)),
+    Osaka : Opt.some(BlobSchedule(target: 9'u64, max: 12'u64, baseFeeUpdateFraction: 5_007_716'u64)),
   ]
 
 func chainConfigForNetwork*(id: NetworkId): ChainConfig =
diff --git a/nimbus/common/common.nim b/nimbus/common/common.nim
index 53853040b8..d22438b2b5 100644
--- a/nimbus/common/common.nim
+++ b/nimbus/common/common.nim
@@ -288,6 +288,9 @@ func toEVMFork*(com: CommonRef, forkDeterminer: ForkDeterminationInfo): EVMFork
   let fork = com.toHardFork(forkDeterminer)
   ToEVMFork[fork]
 
+func toEVMFork*(com: CommonRef, header: Header): EVMFork =
+  com.toEVMFork(forkDeterminationInfo(header))
+
 func isSpuriousOrLater*(com: CommonRef, number: BlockNumber): bool =
   com.toHardFork(number.forkDeterminationInfo) >= Spurious
 
@@ -424,6 +427,10 @@ func targetBlobsPerBlock*(com: CommonRef, fork: HardFork): uint64 =
   doAssert(fork >= Cancun)
   com.config.blobSchedule[fork].expect("blobSchedule initialized").target
 
+func baseFeeUpdateFraction*(com: CommonRef, fork: HardFork): uint64 =
+  doAssert(fork >= Cancun)
+  com.config.blobSchedule[fork].expect("blobSchedule initialized").baseFeeUpdateFraction
+
 # ------------------------------------------------------------------------------
 # Setters
 # ------------------------------------------------------------------------------
diff --git a/nimbus/common/hardforks.nim b/nimbus/common/hardforks.nim
index 25fb58ccab..02b3be36e9 100644
--- a/nimbus/common/hardforks.nim
+++ b/nimbus/common/hardforks.nim
@@ -137,6 +137,7 @@ type
   BlobSchedule* = object
     target*: uint64
     max*   : uint64
+    baseFeeUpdateFraction*: uint64
 
   # if you add more fork block
   # please update forkBlockField constant too
diff --git a/nimbus/constants.nim b/nimbus/constants.nim
index 98696b2835..e23804f1cb 100644
--- a/nimbus/constants.nim
+++ b/nimbus/constants.nim
@@ -86,13 +86,11 @@ const
   GAS_PER_BLOB* = (1 shl 17).uint64 # 2^17
   TARGET_BLOB_GAS_PER_BLOCK* = 393216
   MIN_BLOB_GASPRICE* = 1'u64
-  BLOB_BASE_FEE_UPDATE_FRACTION* = 3338477
   MAX_BLOB_GAS_PER_BLOCK* = 786432
   MAX_BLOBS_PER_BLOCK* = int(MAX_BLOB_GAS_PER_BLOCK div GAS_PER_BLOB)
 
   MAX_BLOB_GAS_PER_BLOCK_ELECTRA* = 1179648
   TARGET_BLOB_GAS_PER_BLOCK_ELECTRA* = 786432
-  BLOB_BASE_FEE_UPDATE_FRACTION_ELECTRA* = 5007716
   MAX_BLOBS_PER_BLOCK_ELECTRA* = int(MAX_BLOB_GAS_PER_BLOCK_ELECTRA div GAS_PER_BLOB)
 
   # EIP-4788 addresses
diff --git a/nimbus/core/eip4844.nim b/nimbus/core/eip4844.nim
index 7bed3200d6..01751d3ae6 100644
--- a/nimbus/core/eip4844.nim
+++ b/nimbus/core/eip4844.nim
@@ -1,5 +1,5 @@
 # Nimbus
-# Copyright (c) 2023-2024 Status Research & Development GmbH
+# Copyright (c) 2023-2025 Status Research & Development GmbH
 # Licensed under either of
 #  * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or
 #    http://www.apache.org/licenses/LICENSE-2.0)
@@ -115,19 +115,22 @@ proc getTotalBlobGas*(versionedHashesLen: int): uint64 =
   GAS_PER_BLOB * versionedHashesLen.uint64
 
 # getBlobBaseFee implements get_data_gas_price from EIP-4844
-func getBlobBaseFee*(excessBlobGas: uint64, electra: bool): UInt256 =
-  let blobBaseFeeUpdateFraction = getBlobBaseFeeUpdateFraction(electra).u256
-  fakeExponential(
-    MIN_BLOB_GASPRICE.u256,
-    excessBlobGas.u256,
-    blobBaseFeeUpdateFraction
-  )
+func getBlobBaseFee*(excessBlobGas: uint64, com: CommonRef, fork: EVMFork): UInt256 =
+  if fork >= FkCancun:
+    let blobBaseFeeUpdateFraction = com.getBlobBaseFeeUpdateFraction(fork).u256
+    fakeExponential(
+      MIN_BLOB_GASPRICE.u256,
+      excessBlobGas.u256,
+      blobBaseFeeUpdateFraction
+    )
+  else:
+    0.u256
 
 proc calcDataFee*(versionedHashesLen: int,
                   excessBlobGas: uint64,
-                  electra: bool): UInt256 =
+                  com: CommonRef, fork: EVMFork): UInt256 =
   getTotalBlobGas(versionedHashesLen).u256 *
-    getBlobBaseFee(excessBlobGas, electra)
+    getBlobBaseFee(excessBlobGas, com, fork)
 
 func blobGasUsed(txs: openArray[Transaction]): uint64 =
   for tx in txs:
diff --git a/nimbus/core/eip7691.nim b/nimbus/core/eip7691.nim
index 2cadf76ed9..14742e897e 100644
--- a/nimbus/core/eip7691.nim
+++ b/nimbus/core/eip7691.nim
@@ -24,10 +24,6 @@ func getTargetBlobGasPerBlock*(electra: bool): uint64 =
   if electra: TARGET_BLOB_GAS_PER_BLOCK_ELECTRA.uint64
   else: TARGET_BLOB_GAS_PER_BLOCK.uint64
 
-func getBlobBaseFeeUpdateFraction*(electra: bool): uint64 =
-  if electra: BLOB_BASE_FEE_UPDATE_FRACTION_ELECTRA.uint64
-  else: BLOB_BASE_FEE_UPDATE_FRACTION.uint64
-
 const
   EVMForkToFork: array[FkCancun..EVMFork.high, HardFork] = [
     Cancun,
@@ -38,3 +34,7 @@ const
 func getMaxBlobsPerBlock*(com: CommonRef, fork: EVMFork): uint64 =
   doAssert(fork >= FkCancun)
   com.maxBlobsPerBlock(EVMForkToFork[fork])
+
+func getBlobBaseFeeUpdateFraction*(com: CommonRef, fork: EVMFork): uint64 =
+  doAssert(fork >= FkCancun)
+  com.baseFeeUpdateFraction(EVMForkToFork[fork])
diff --git a/nimbus/core/tx_pool/tx_desc.nim b/nimbus/core/tx_pool/tx_desc.nim
index 289bcb1717..ea2091884a 100644
--- a/nimbus/core/tx_pool/tx_desc.nim
+++ b/nimbus/core/tx_pool/tx_desc.nim
@@ -184,8 +184,7 @@ proc classifyValid(xp: TxPoolRef; tx: Transaction, sender: Address): bool =
   if tx.txType == TxEip4844:
     let
       excessBlobGas = xp.excessBlobGas
-      electra = xp.vmState.fork >= FkPrague
-      blobGasPrice = getBlobBaseFee(excessBlobGas, electra)
+      blobGasPrice = getBlobBaseFee(excessBlobGas, xp.vmState.com, xp.vmState.fork)
     if tx.maxFeePerBlobGas < blobGasPrice:
       debug "Invalid transaction: maxFeePerBlobGas lower than blobGasPrice",
         maxFeePerBlobGas = tx.maxFeePerBlobGas,
diff --git a/nimbus/core/validate.nim b/nimbus/core/validate.nim
index dc600e7b75..17bc6751c2 100644
--- a/nimbus/core/validate.nim
+++ b/nimbus/core/validate.nim
@@ -346,7 +346,7 @@ proc validateTransaction*(
 
   if tx.txType == TxEip4844:
     # ensure that the user was willing to at least pay the current data gasprice
-    let blobGasPrice = getBlobBaseFee(excessBlobGas, fork >= FkPrague)
+    let blobGasPrice = getBlobBaseFee(excessBlobGas, com, fork)
     if tx.maxFeePerBlobGas < blobGasPrice:
       return err("invalid tx: maxFeePerBlobGas smaller than blobGasPrice. " &
         &"maxFeePerBlobGas={tx.maxFeePerBlobGas}, blobGasPrice={blobGasPrice}")
diff --git a/nimbus/rpc/oracle.nim b/nimbus/rpc/oracle.nim
index 0a26073b06..6a8498a131 100644
--- a/nimbus/rpc/oracle.nim
+++ b/nimbus/rpc/oracle.nim
@@ -1,5 +1,5 @@
 # Nimbus
-# Copyright (c) 2024 Status Research & Development GmbH
+# Copyright (c) 2024-2025 Status Research & Development GmbH
 # Licensed under either of
 #  * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE))
 #  * MIT license ([LICENSE-MIT](LICENSE-MIT))
@@ -100,13 +100,13 @@ func calcBaseFee(com: CommonRef, bc: BlockContent): UInt256 =
 # fills in the rest of the fields.
 proc processBlock(oracle: Oracle, bc: BlockContent, percentiles: openArray[float64]): ProcessedFees =
   let
-    electra = com.isPragueOrLater(bc.header.timestamp)
+    fork = com.toEVMFork(bc.header)
     maxBlobGasPerBlock = getMaxBlobGasPerBlock(electra)
   result = ProcessedFees(
     baseFee: bc.header.baseFeePerGas.get(0.u256),
-    blobBaseFee: getBlobBaseFee(bc.header.excessBlobGas.get(0'u64), electra),
+    blobBaseFee: getBlobBaseFee(bc.header.excessBlobGas.get(0'u64), com, fork),
     nextBaseFee: calcBaseFee(oracle.com, bc),
-    nextBlobBaseFee: getBlobBaseFee(calcExcessBlobGas(bc.header, electra), electra),
+    nextBlobBaseFee: getBlobBaseFee(calcExcessBlobGas(bc.header, com, fork), com, fork),
     gasUsedRatio: float64(bc.header.gasUsed) / float64(bc.header.gasLimit),
     blobGasUsedRatio: float64(bc.header.blobGasUsed.get(0'u64)) / float64(maxBlobGasPerBlock)
   )
diff --git a/nimbus/rpc/rpc_utils.nim b/nimbus/rpc/rpc_utils.nim
index 4475a05f4a..176bb3c864 100644
--- a/nimbus/rpc/rpc_utils.nim
+++ b/nimbus/rpc/rpc_utils.nim
@@ -1,5 +1,5 @@
 # Nimbus
-# Copyright (c) 2018-2024 Status Research & Development GmbH
+# Copyright (c) 2018-2025 Status Research & Development GmbH
 # Licensed under either of
 #  * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE))
 #  * MIT license ([LICENSE-MIT](LICENSE-MIT))
@@ -180,7 +180,7 @@ proc populateBlockObject*(blockHash: Hash32,
   result.requestsHash = header.requestsHash
 
 proc populateReceipt*(receipt: Receipt, gasUsed: GasInt, tx: Transaction,
-                      txIndex: uint64, header: Header, electra: bool): ReceiptObject =
+                      txIndex: uint64, header: Header, com: CommonRef): ReceiptObject =
   let sender = tx.recoverSender()
   var res = ReceiptObject()
   res.transactionHash = tx.rlpHash
@@ -236,7 +236,7 @@ proc populateReceipt*(receipt: Receipt, gasUsed: GasInt, tx: Transaction,
 
   if tx.txType == TxEip4844:
     res.blobGasUsed = Opt.some(Quantity(tx.versionedHashes.len.uint64 * GAS_PER_BLOB.uint64))
-    res.blobGasPrice = Opt.some(getBlobBaseFee(header.excessBlobGas.get(0'u64), electra))
+    res.blobGasPrice = Opt.some(getBlobBaseFee(header.excessBlobGas.get(0'u64), com, com.toEVMFork(header)))
 
   return res
 
diff --git a/nimbus/rpc/server_api.nim b/nimbus/rpc/server_api.nim
index 468f4e7758..c4ef733805 100644
--- a/nimbus/rpc/server_api.nim
+++ b/nimbus/rpc/server_api.nim
@@ -368,7 +368,7 @@ proc setupServerAPI*(api: ServerAPIRef, server: RpcServer, ctx: EthContext) =
         let gasUsed = receipt.cumulativeGasUsed - prevGasUsed
         prevGasUsed = receipt.cumulativeGasUsed
         if idx == txDetails.index:
-          return populateReceipt(receipt, gasUsed, tx, txDetails.index, header, api.com.isPragueOrLater(header.timestamp))
+          return populateReceipt(receipt, gasUsed, tx, txDetails.index, header, api.com)
         idx.inc
     else:
       # Receipt in memory
@@ -382,8 +382,7 @@ proc setupServerAPI*(api: ServerAPIRef, server: RpcServer, ctx: EthContext) =
         if txid == idx:
           return populateReceipt(
             receipt, gasUsed, blkdesc.blk.transactions[txid], txid, blkdesc.blk.header,
-            api.com.isPragueOrLater(blkdesc.blk.header.timestamp)
-          )
+            api.com)
 
         idx.inc
 
@@ -666,7 +665,7 @@ proc setupServerAPI*(api: ServerAPIRef, server: RpcServer, ctx: EthContext) =
       for receipt in receipts:
         let gasUsed = receipt.cumulativeGasUsed - prevGasUsed
         prevGasUsed = receipt.cumulativeGasUsed
-        recs.add populateReceipt(receipt, gasUsed, txs[index], index, header, api.com.isPragueOrLater(header.timestamp))
+        recs.add populateReceipt(receipt, gasUsed, txs[index], index, header, api.com)
         inc index
       return Opt.some(recs)
     except CatchableError:
@@ -692,7 +691,7 @@ proc setupServerAPI*(api: ServerAPIRef, server: RpcServer, ctx: EthContext) =
     if header.excessBlobGas.isNone:
       raise newException(ValueError, "excessBlobGas missing from latest header")
     let blobBaseFee =
-      getBlobBaseFee(header.excessBlobGas.get, api.com.isPragueOrLater(header.timestamp)) * header.blobGasUsed.get.u256
+      getBlobBaseFee(header.excessBlobGas.get, api.com, api.com.toEVMFork(header)) * header.blobGasUsed.get.u256
     if blobBaseFee > high(uint64).u256:
       raise newException(ValueError, "blobBaseFee is bigger than uint64.max")
     return w3Qty blobBaseFee.truncate(uint64)
diff --git a/nimbus/transaction/call_common.nim b/nimbus/transaction/call_common.nim
index fff91ed248..703fd5c590 100644
--- a/nimbus/transaction/call_common.nim
+++ b/nimbus/transaction/call_common.nim
@@ -135,7 +135,7 @@ proc setupHost(call: CallParams, keepStack: bool): TransactionHost =
     origin         : call.origin.get(call.sender),
     gasPrice       : call.gasPrice,
     versionedHashes: call.versionedHashes,
-    blobBaseFee    : getBlobBaseFee(vmState.blockCtx.excessBlobGas, vmState.fork >= FkPrague),
+    blobBaseFee    : getBlobBaseFee(vmState.blockCtx.excessBlobGas, vmState.com, vmState.fork),
   )
 
   # reset global gasRefund counter each time
@@ -232,7 +232,7 @@ proc prepareToRunComputation(host: TransactionHost, call: CallParams) =
       # EIP-4844
       if fork >= FkCancun:
         let blobFee = calcDataFee(call.versionedHashes.len,
-          vmState.blockCtx.excessBlobGas, fork >= FkPrague)
+          vmState.blockCtx.excessBlobGas, vmState.com, fork)
         db.subBalance(call.sender, blobFee)
 
 proc calculateAndPossiblyRefundGas(host: TransactionHost, call: CallParams): GasInt =
diff --git a/tests/customgenesis/blobschedule_cancun_osaka.json b/tests/customgenesis/blobschedule_cancun_osaka.json
index c6b7414e33..314b8b7998 100644
--- a/tests/customgenesis/blobschedule_cancun_osaka.json
+++ b/tests/customgenesis/blobschedule_cancun_osaka.json
@@ -16,11 +16,13 @@
     "blobSchedule": {
       "cancun": {
         "target": 3,
-        "max": 6
+        "max": 6,
+        "baseFeeUpdateFraction": 3338477
       },
       "osaka": {
         "target": 6,
-        "max": 9
+        "max": 9,
+        "baseFeeUpdateFraction": 5007716
       }
     }
   }
diff --git a/tests/customgenesis/blobschedule_cancun_prague.json b/tests/customgenesis/blobschedule_cancun_prague.json
index 3ca75e5fd5..89477a04d4 100644
--- a/tests/customgenesis/blobschedule_cancun_prague.json
+++ b/tests/customgenesis/blobschedule_cancun_prague.json
@@ -16,11 +16,13 @@
     "blobSchedule": {
       "cancun": {
         "target": 3,
-        "max": 6
+        "max": 6,
+        "baseFeeUpdateFraction": 3338477
       },
       "prague": {
         "target": 6,
-        "max": 9
+        "max": 9,
+        "baseFeeUpdateFraction": 5007716
       }
     }
   }
diff --git a/tests/customgenesis/blobschedule_nobasefee.json b/tests/customgenesis/blobschedule_nobasefee.json
new file mode 100644
index 0000000000..3ca75e5fd5
--- /dev/null
+++ b/tests/customgenesis/blobschedule_nobasefee.json
@@ -0,0 +1,27 @@
+{
+  "config": {
+    "chainId": 7,
+    "homesteadBlock": 0,
+    "eip150Block": 0,
+    "eip150Hash": "0x5de1ee4135274003348e80b788e5afa4b18b18d320a5622218d5c493fedf5689",
+    "eip155Block": 0,
+    "eip158Block": 0,
+    "byzantiumBlock": 0,
+    "constantinopleBlock": 0,
+    "petersburgBlock": 0,
+    "istanbulBlock": 0,
+    "muirGlacierBlock": 0,
+    "berlinBlock": 0,
+    "londonBlock": 0,
+    "blobSchedule": {
+      "cancun": {
+        "target": 3,
+        "max": 6
+      },
+      "prague": {
+        "target": 6,
+        "max": 9
+      }
+    }
+  }
+}
diff --git a/tests/customgenesis/blobschedule_prague.json b/tests/customgenesis/blobschedule_prague.json
index 932db723d4..083ce9c3b6 100644
--- a/tests/customgenesis/blobschedule_prague.json
+++ b/tests/customgenesis/blobschedule_prague.json
@@ -16,7 +16,8 @@
     "blobSchedule": {
       "prague": {
         "target": 6,
-        "max": 9
+        "max": 9,
+        "baseFeeUpdateFraction": 5007716
       }
     }
   }
diff --git a/tests/customgenesis/merge.json b/tests/customgenesis/merge.json
index 2948a8cb6f..533d1e08e6 100644
--- a/tests/customgenesis/merge.json
+++ b/tests/customgenesis/merge.json
@@ -11,16 +11,18 @@
     "petersburgBlock": 0,
     "istanbulBlock": 0,
     "muirGlacierBlock": 0,
-    "berlinBlock": 0,    
+    "berlinBlock": 0,
     "londonBlock": 0,
     "blobSchedule": {
       "cancun": {
         "target": 3,
-        "max": 6
+        "max": 6,
+        "baseFeeUpdateFraction": 3338477
       },
       "prague": {
         "target": 6,
-        "max": 9
+        "max": 9,
+        "baseFeeUpdateFraction": 5007716
       }
     }
   },
diff --git a/tests/test_genesis.nim b/tests/test_genesis.nim
index 09c37d8595..4a62d82e9f 100644
--- a/tests/test_genesis.nim
+++ b/tests/test_genesis.nim
@@ -152,28 +152,34 @@ proc customGenesisTest() =
       ]) == EmptyRequestsHash
 
     test "BlobSchedule":
-      template validateBlobSchedule(cg, fork, tgt, mx) =
+      template validateBlobSchedule(cg, fork, tgt, mx, fee) =
         check cg.config.blobSchedule[fork].isSome
         if cg.config.blobSchedule[fork].isSome:
           let bs = cg.config.blobSchedule[fork].get
           check bs.target == tgt
           check bs.max == mx
+          check bs.baseFeeUpdateFraction == fee
 
       var cg: NetworkParams
       check loadNetworkParams("blobschedule_cancun_prague.json".findFilePath, cg)
-      validateBlobSchedule(cg, Cancun, 3, 6)
-      validateBlobSchedule(cg, Prague, 6, 9)
-      validateBlobSchedule(cg, Osaka, 6, 9)
+      validateBlobSchedule(cg, Cancun, 3, 6, 3338477)
+      validateBlobSchedule(cg, Prague, 6, 9, 5007716)
+      validateBlobSchedule(cg, Osaka, 6, 9, 5007716)
 
       check loadNetworkParams("blobschedule_cancun_osaka.json".findFilePath, cg)
-      validateBlobSchedule(cg, Cancun, 3, 6)
-      validateBlobSchedule(cg, Prague, 3, 6)
-      validateBlobSchedule(cg, Osaka, 6, 9)
+      validateBlobSchedule(cg, Cancun, 3, 6, 3338477)
+      validateBlobSchedule(cg, Prague, 3, 6, 3338477)
+      validateBlobSchedule(cg, Osaka, 6, 9, 5007716)
 
       check loadNetworkParams("blobschedule_prague.json".findFilePath, cg)
-      validateBlobSchedule(cg, Cancun, 3, 6) # default fallback case
-      validateBlobSchedule(cg, Prague, 6, 9)
-      validateBlobSchedule(cg, Osaka, 6, 9)
+      validateBlobSchedule(cg, Cancun, 3, 6, 3338477) # default fallback case
+      validateBlobSchedule(cg, Prague, 6, 9, 5007716)
+      validateBlobSchedule(cg, Osaka, 6, 9, 5007716)
+
+      check loadNetworkParams("blobschedule_nobasefee.json".findFilePath, cg)
+      validateBlobSchedule(cg, Cancun, 3, 6, 3338477)
+      validateBlobSchedule(cg, Prague, 6, 9, 3338477)
+      validateBlobSchedule(cg, Osaka, 6, 9, 3338477)
 
 proc genesisMain*() =
   genesisTest()
diff --git a/tests/test_txpool.nim b/tests/test_txpool.nim
index 79175a3f3f..2af6d692e1 100644
--- a/tests/test_txpool.nim
+++ b/tests/test_txpool.nim
@@ -642,7 +642,7 @@ proc txPoolMain*() =
       # override current blobSchedule
       let bs = cc.blobSchedule[Cancun]
       cc.blobSchedule[Cancun] = Opt.some(
-        BlobSchedule(target: 2, max: 3)
+        BlobSchedule(target: 2, max: 3, baseFeeUpdateFraction: 3338477)
       )
 
       # allow 3 blobs