diff --git a/nimbus/common/chain_config_hash.nim b/nimbus/common/chain_config_hash.nim
index c11df4ff4..e78da647d 100644
--- a/nimbus/common/chain_config_hash.nim
+++ b/nimbus/common/chain_config_hash.nim
@@ -79,7 +79,7 @@ func calcHash*(networkId: NetworkId, conf: ChainConfig, genesis: Genesis): Hash3
   var ctx: sha256
   ctx.init()
   ctx.update(networkId)
-  ctx.update(conf)
+  ctx.update(conf.chainId)
   if genesis.isNil.not:
     ctx.update(genesis)
   ctx.finish(result.data)
diff --git a/nimbus/config.nim b/nimbus/config.nim
index a8548574a..e64f1bbee 100644
--- a/nimbus/config.nim
+++ b/nimbus/config.nim
@@ -417,6 +417,11 @@ type
       desc: "Print RDB statistics at exit"
       name: "debug-rdb-print-stats".}: bool
 
+    rewriteDatadirId* {.
+      hidden
+      desc: "Rewrite selected network config hash to database"
+      name: "debug-rewrite-datadir-id".}: bool
+
     case cmd* {.
       command
       defaultValue: NimbusCmd.noCommand }: NimbusCmd
diff --git a/nimbus/nimbus_execution_client.nim b/nimbus/nimbus_execution_client.nim
index 5a9ab9443..6010037db 100644
--- a/nimbus/nimbus_execution_client.nim
+++ b/nimbus/nimbus_execution_client.nim
@@ -156,17 +156,24 @@ proc setupMetrics(nimbus: NimbusNode, conf: NimbusConf) =
     waitFor nimbus.metricsServer.start()
 
 proc preventLoadingDataDirForTheWrongNetwork(db: CoreDbRef; conf: NimbusConf) =
+  proc writeDataDirId(kvt: CoreDbKvtRef, calculatedId: Hash32) =
+    info "Writing data dir ID", ID=calculatedId
+    kvt.put(dataDirIdKey().toOpenArray, calculatedId.data).isOkOr:
+      fatal "Cannot write data dir ID", ID=calculatedId
+      quit(QuitFailure)
+      
   let
     kvt = db.ctx.getKvt()
     calculatedId = calcHash(conf.networkId, conf.networkParams)
     dataDirIdBytes = kvt.get(dataDirIdKey().toOpenArray).valueOr:
       # an empty database
-      info "Writing data dir ID", ID=calculatedId
-      kvt.put(dataDirIdKey().toOpenArray, calculatedId.data).isOkOr:
-        fatal "Cannot write data dir ID", ID=calculatedId
-        quit(QuitFailure)
+      writeDataDirId(kvt, calculatedId)
       return
 
+  if conf.rewriteDatadirId:
+    writeDataDirId(kvt, calculatedId)
+    return
+  
   if calculatedId.data != dataDirIdBytes:
     fatal "Data dir already initialized with other network configuration",
       get=dataDirIdBytes.toHex,