diff --git a/nimbus/db/db_chain.nim b/nimbus/db/db_chain.nim
index 534bd1c9e..31f1b5486 100644
--- a/nimbus/db/db_chain.nim
+++ b/nimbus/db/db_chain.nim
@@ -10,12 +10,13 @@ import
   ranges, state_db, eth/trie/[hexary, db],
   eth/[common, rlp], byteutils, chronicles,
   ../errors,  ../constants, ./storage_types,
-  ../utils
+  ../utils, ../config
 
 type
   BaseChainDB* = ref object
     db*       : TrieDatabaseRef
     pruneTrie*: bool
+    config*   : ChainConfig
 
   #KeyType = enum
   #  blockNumberToHash
@@ -25,10 +26,11 @@ type
     blockNumber: BlockNumber
     index: int
 
-proc newBaseChainDB*(db: TrieDatabaseRef, pruneTrie: bool = true): BaseChainDB =
+proc newBaseChainDB*(db: TrieDatabaseRef, pruneTrie: bool = true, id: PublicNetwork = MainNet): BaseChainDB =
   new(result)
   result.db = db
   result.pruneTrie = pruneTrie
+  result.config = publicChainConfig(id)
 
 proc `$`*(db: BaseChainDB): string =
   result = "BaseChainDB"
diff --git a/nimbus/nimbus.nim b/nimbus/nimbus.nim
index 4bb37ad4b..19baef020 100644
--- a/nimbus/nimbus.nim
+++ b/nimbus/nimbus.nim
@@ -66,7 +66,9 @@ proc start(): NimbusObject =
 
   createDir(conf.dataDir)
   let trieDB = trieDB newChainDb(conf.dataDir)
-  let chainDB = newBaseChainDB(trieDB, conf.prune == PruneMode.Full)
+  let chainDB = newBaseChainDB(trieDB,
+    conf.prune == PruneMode.Full,
+    conf.net.networkId.toPublicNetwork())
 
   if canonicalHeadHashKey().toOpenArray notin trieDB:
     initializeEmptyDb(chainDb)
diff --git a/nimbus/p2p/dao.nim b/nimbus/p2p/dao.nim
new file mode 100644
index 000000000..3b5ad1ba1
--- /dev/null
+++ b/nimbus/p2p/dao.nim
@@ -0,0 +1,143 @@
+import eth/common, byteutils, ../db/state_db
+
+const
+  # DAOForkBlockExtra is the block header extra-data field to set for the DAO fork
+  # point and a number of consecutive blocks to allow fast/light syncers to correctly
+  # pick the side they want  ("dao-hard-fork").
+  DAOForkBlockExtra* = "0x64616f2d686172642d666f726b"
+
+  # DAOForkExtraRange is the number of consecutive blocks from the DAO fork point
+  # to override the extra-data in to prevent no-fork attacks.
+  DAOForkExtraRange* = 10
+
+  # DAORefundContract is the address of the refund contract to send DAO balances to.
+  DAORefundContract: EthAddress = hexToByteArray[20]("0xbf4ed7b27f1d666546e30d74d50d173d20bca754")
+
+  DAODrainList = [
+    hexToByteArray[20]("0xd4fe7bc31cedb7bfb8a345f31e668033056b2728"),
+    hexToByteArray[20]("0xb3fb0e5aba0e20e5c49d252dfd30e102b171a425"),
+    hexToByteArray[20]("0x2c19c7f9ae8b751e37aeb2d93a699722395ae18f"),
+    hexToByteArray[20]("0xecd135fa4f61a655311e86238c92adcd779555d2"),
+    hexToByteArray[20]("0x1975bd06d486162d5dc297798dfc41edd5d160a7"),
+    hexToByteArray[20]("0xa3acf3a1e16b1d7c315e23510fdd7847b48234f6"),
+    hexToByteArray[20]("0x319f70bab6845585f412ec7724b744fec6095c85"),
+    hexToByteArray[20]("0x06706dd3f2c9abf0a21ddcc6941d9b86f0596936"),
+    hexToByteArray[20]("0x5c8536898fbb74fc7445814902fd08422eac56d0"),
+    hexToByteArray[20]("0x6966ab0d485353095148a2155858910e0965b6f9"),
+    hexToByteArray[20]("0x779543a0491a837ca36ce8c635d6154e3c4911a6"),
+    hexToByteArray[20]("0x2a5ed960395e2a49b1c758cef4aa15213cfd874c"),
+    hexToByteArray[20]("0x5c6e67ccd5849c0d29219c4f95f1a7a93b3f5dc5"),
+    hexToByteArray[20]("0x9c50426be05db97f5d64fc54bf89eff947f0a321"),
+    hexToByteArray[20]("0x200450f06520bdd6c527622a273333384d870efb"),
+    hexToByteArray[20]("0xbe8539bfe837b67d1282b2b1d61c3f723966f049"),
+    hexToByteArray[20]("0x6b0c4d41ba9ab8d8cfb5d379c69a612f2ced8ecb"),
+    hexToByteArray[20]("0xf1385fb24aad0cd7432824085e42aff90886fef5"),
+    hexToByteArray[20]("0xd1ac8b1ef1b69ff51d1d401a476e7e612414f091"),
+    hexToByteArray[20]("0x8163e7fb499e90f8544ea62bbf80d21cd26d9efd"),
+    hexToByteArray[20]("0x51e0ddd9998364a2eb38588679f0d2c42653e4a6"),
+    hexToByteArray[20]("0x627a0a960c079c21c34f7612d5d230e01b4ad4c7"),
+    hexToByteArray[20]("0xf0b1aa0eb660754448a7937c022e30aa692fe0c5"),
+    hexToByteArray[20]("0x24c4d950dfd4dd1902bbed3508144a54542bba94"),
+    hexToByteArray[20]("0x9f27daea7aca0aa0446220b98d028715e3bc803d"),
+    hexToByteArray[20]("0xa5dc5acd6a7968a4554d89d65e59b7fd3bff0f90"),
+    hexToByteArray[20]("0xd9aef3a1e38a39c16b31d1ace71bca8ef58d315b"),
+    hexToByteArray[20]("0x63ed5a272de2f6d968408b4acb9024f4cc208ebf"),
+    hexToByteArray[20]("0x6f6704e5a10332af6672e50b3d9754dc460dfa4d"),
+    hexToByteArray[20]("0x77ca7b50b6cd7e2f3fa008e24ab793fd56cb15f6"),
+    hexToByteArray[20]("0x492ea3bb0f3315521c31f273e565b868fc090f17"),
+    hexToByteArray[20]("0x0ff30d6de14a8224aa97b78aea5388d1c51c1f00"),
+    hexToByteArray[20]("0x9ea779f907f0b315b364b0cfc39a0fde5b02a416"),
+    hexToByteArray[20]("0xceaeb481747ca6c540a000c1f3641f8cef161fa7"),
+    hexToByteArray[20]("0xcc34673c6c40e791051898567a1222daf90be287"),
+    hexToByteArray[20]("0x579a80d909f346fbfb1189493f521d7f48d52238"),
+    hexToByteArray[20]("0xe308bd1ac5fda103967359b2712dd89deffb7973"),
+    hexToByteArray[20]("0x4cb31628079fb14e4bc3cd5e30c2f7489b00960c"),
+    hexToByteArray[20]("0xac1ecab32727358dba8962a0f3b261731aad9723"),
+    hexToByteArray[20]("0x4fd6ace747f06ece9c49699c7cabc62d02211f75"),
+    hexToByteArray[20]("0x440c59b325d2997a134c2c7c60a8c61611212bad"),
+    hexToByteArray[20]("0x4486a3d68fac6967006d7a517b889fd3f98c102b"),
+    hexToByteArray[20]("0x9c15b54878ba618f494b38f0ae7443db6af648ba"),
+    hexToByteArray[20]("0x27b137a85656544b1ccb5a0f2e561a5703c6a68f"),
+    hexToByteArray[20]("0x21c7fdb9ed8d291d79ffd82eb2c4356ec0d81241"),
+    hexToByteArray[20]("0x23b75c2f6791eef49c69684db4c6c1f93bf49a50"),
+    hexToByteArray[20]("0x1ca6abd14d30affe533b24d7a21bff4c2d5e1f3b"),
+    hexToByteArray[20]("0xb9637156d330c0d605a791f1c31ba5890582fe1c"),
+    hexToByteArray[20]("0x6131c42fa982e56929107413a9d526fd99405560"),
+    hexToByteArray[20]("0x1591fc0f688c81fbeb17f5426a162a7024d430c2"),
+    hexToByteArray[20]("0x542a9515200d14b68e934e9830d91645a980dd7a"),
+    hexToByteArray[20]("0xc4bbd073882dd2add2424cf47d35213405b01324"),
+    hexToByteArray[20]("0x782495b7b3355efb2833d56ecb34dc22ad7dfcc4"),
+    hexToByteArray[20]("0x58b95c9a9d5d26825e70a82b6adb139d3fd829eb"),
+    hexToByteArray[20]("0x3ba4d81db016dc2890c81f3acec2454bff5aada5"),
+    hexToByteArray[20]("0xb52042c8ca3f8aa246fa79c3feaa3d959347c0ab"),
+    hexToByteArray[20]("0xe4ae1efdfc53b73893af49113d8694a057b9c0d1"),
+    hexToByteArray[20]("0x3c02a7bc0391e86d91b7d144e61c2c01a25a79c5"),
+    hexToByteArray[20]("0x0737a6b837f97f46ebade41b9bc3e1c509c85c53"),
+    hexToByteArray[20]("0x97f43a37f595ab5dd318fb46e7a155eae057317a"),
+    hexToByteArray[20]("0x52c5317c848ba20c7504cb2c8052abd1fde29d03"),
+    hexToByteArray[20]("0x4863226780fe7c0356454236d3b1c8792785748d"),
+    hexToByteArray[20]("0x5d2b2e6fcbe3b11d26b525e085ff818dae332479"),
+    hexToByteArray[20]("0x5f9f3392e9f62f63b8eac0beb55541fc8627f42c"),
+    hexToByteArray[20]("0x057b56736d32b86616a10f619859c6cd6f59092a"),
+    hexToByteArray[20]("0x9aa008f65de0b923a2a4f02012ad034a5e2e2192"),
+    hexToByteArray[20]("0x304a554a310c7e546dfe434669c62820b7d83490"),
+    hexToByteArray[20]("0x914d1b8b43e92723e64fd0a06f5bdb8dd9b10c79"),
+    hexToByteArray[20]("0x4deb0033bb26bc534b197e61d19e0733e5679784"),
+    hexToByteArray[20]("0x07f5c1e1bc2c93e0402f23341973a0e043f7bf8a"),
+    hexToByteArray[20]("0x35a051a0010aba705c9008d7a7eff6fb88f6ea7b"),
+    hexToByteArray[20]("0x4fa802324e929786dbda3b8820dc7834e9134a2a"),
+    hexToByteArray[20]("0x9da397b9e80755301a3b32173283a91c0ef6c87e"),
+    hexToByteArray[20]("0x8d9edb3054ce5c5774a420ac37ebae0ac02343c6"),
+    hexToByteArray[20]("0x0101f3be8ebb4bbd39a2e3b9a3639d4259832fd9"),
+    hexToByteArray[20]("0x5dc28b15dffed94048d73806ce4b7a4612a1d48f"),
+    hexToByteArray[20]("0xbcf899e6c7d9d5a215ab1e3444c86806fa854c76"),
+    hexToByteArray[20]("0x12e626b0eebfe86a56d633b9864e389b45dcb260"),
+    hexToByteArray[20]("0xa2f1ccba9395d7fcb155bba8bc92db9bafaeade7"),
+    hexToByteArray[20]("0xec8e57756626fdc07c63ad2eafbd28d08e7b0ca5"),
+    hexToByteArray[20]("0xd164b088bd9108b60d0ca3751da4bceb207b0782"),
+    hexToByteArray[20]("0x6231b6d0d5e77fe001c2a460bd9584fee60d409b"),
+    hexToByteArray[20]("0x1cba23d343a983e9b5cfd19496b9a9701ada385f"),
+    hexToByteArray[20]("0xa82f360a8d3455c5c41366975bde739c37bfeb8a"),
+    hexToByteArray[20]("0x9fcd2deaff372a39cc679d5c5e4de7bafb0b1339"),
+    hexToByteArray[20]("0x005f5cee7a43331d5a3d3eec71305925a62f34b6"),
+    hexToByteArray[20]("0x0e0da70933f4c7849fc0d203f5d1d43b9ae4532d"),
+    hexToByteArray[20]("0xd131637d5275fd1a68a3200f4ad25c71a2a9522e"),
+    hexToByteArray[20]("0xbc07118b9ac290e4622f5e77a0853539789effbe"),
+    hexToByteArray[20]("0x47e7aa56d6bdf3f36be34619660de61275420af8"),
+    hexToByteArray[20]("0xacd87e28b0c9d1254e868b81cba4cc20d9a32225"),
+    hexToByteArray[20]("0xadf80daec7ba8dcf15392f1ac611fff65d94f880"),
+    hexToByteArray[20]("0x5524c55fb03cf21f549444ccbecb664d0acad706"),
+    hexToByteArray[20]("0x40b803a9abce16f50f36a77ba41180eb90023925"),
+    hexToByteArray[20]("0xfe24cdd8648121a43a7c86d289be4dd2951ed49f"),
+    hexToByteArray[20]("0x17802f43a0137c506ba92291391a8a8f207f487d"),
+    hexToByteArray[20]("0x253488078a4edf4d6f42f113d1e62836a942cf1a"),
+    hexToByteArray[20]("0x86af3e9626fce1957c82e88cbf04ddf3a2ed7915"),
+    hexToByteArray[20]("0xb136707642a4ea12fb4bae820f03d2562ebff487"),
+    hexToByteArray[20]("0xdbe9b615a3ae8709af8b93336ce9b477e4ac0940"),
+    hexToByteArray[20]("0xf14c14075d6c4ed84b86798af0956deef67365b5"),
+    hexToByteArray[20]("0xca544e5c4687d109611d0f8f928b53a25af72448"),
+    hexToByteArray[20]("0xaeeb8ff27288bdabc0fa5ebb731b6f409507516c"),
+    hexToByteArray[20]("0xcbb9d3703e651b0d496cdefb8b92c25aeb2171f7"),
+    hexToByteArray[20]("0x6d87578288b6cb5549d5076a207456a1f6a63dc0"),
+    hexToByteArray[20]("0xb2c6f0dfbb716ac562e2d85d6cb2f8d5ee87603e"),
+    hexToByteArray[20]("0xaccc230e8a6e5be9160b8cdf2864dd2a001c28b6"),
+    hexToByteArray[20]("0x2b3455ec7fedf16e646268bf88846bd7a2319bb2"),
+    hexToByteArray[20]("0x4613f3bca5c44ea06337a9e439fbc6d42e501d0a"),
+    hexToByteArray[20]("0xd343b217de44030afaa275f54d31a9317c7f441e"),
+    hexToByteArray[20]("0x84ef4b2357079cd7a7c69fd7a37cd0609a679106"),
+    hexToByteArray[20]("0xda2fef9e4a3230988ff17df2165440f37e8b1708"),
+    hexToByteArray[20]("0xf4c64518ea10f995918a454158c6b61407ea345c"),
+    hexToByteArray[20]("0x7602b46df5390e432ef1c307d4f2c9ff6d65cc97"),
+    hexToByteArray[20]("0xbb9bc244d798123fde783fcc1c72d3bb8c189413"),
+    hexToByteArray[20]("0x807640a13483f8ac783c557fcdf27be11ea4ac7a")
+  ]
+
+# ApplyDAOHardFork modifies the state database according to the DAO hard-fork
+# rules, transferring all balances of a set of DAO accounts to a single refund
+# contract.
+proc applyDAOHardFork*(statedb: var AccountStateDB) =
+  const zero = 0.u256
+  # Move every DAO account and extra-balance account funds into the refund contract
+  for address in DAODrainList:
+    statedb.addBalance(DAORefundContract, statedb.getBalance(address))
+    statedb.setBalance(address, zero)
diff --git a/nimbus/p2p/executor.nim b/nimbus/p2p/executor.nim
index 057da46db..d0b09e418 100644
--- a/nimbus/p2p/executor.nim
+++ b/nimbus/p2p/executor.nim
@@ -4,7 +4,8 @@ import options,
   ../utils, ../constants, ../transaction,
   ../vm_state, ../vm_types, ../vm_state_transactions,
   ../vm/[computation, message],
-  ../vm/interpreter/vm_forks
+  ../vm/interpreter/vm_forks,
+  ./dao
 
 proc processTransaction*(tx: Transaction, sender: EthAddress, vmState: BaseVMState, forkOverride=none(Fork)): GasInt =
   ## Process the transaction, write the results to db.
@@ -72,6 +73,10 @@ proc makeReceipt(vmState: BaseVMState, cumulativeGasUsed: GasInt, fork = FkFront
 proc processBlock*(chainDB: BaseChainDB, header: BlockHeader, body: BlockBody, vmState: BaseVMState): ValidationResult =
   let blockReward = 5.u256 * pow(10.u256, 18) # 5 ETH
 
+  if chainDB.config.daoForkSupport and header.blockNumber == chainDB.config.daoForkBlock:
+    vmState.mutateStateDB:
+      db.applyDAOHardFork()
+
   if body.transactions.calcTxRoot != header.txRoot:
     debug "Mismatched txRoot", blockNumber=header.blockNumber
     return ValidationResult.Error