diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 850de6d28..68dae1f4d 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -64,7 +64,7 @@ jobs:
         include:
           - target:
               os: linux
-            builder: ubuntu-18.04
+            builder: ubuntu-20.04
             shell: bash
           - target:
               os: macos
diff --git a/.github/workflows/fluffy.yml b/.github/workflows/fluffy.yml
index a96ab04c4..b1a00e42d 100644
--- a/.github/workflows/fluffy.yml
+++ b/.github/workflows/fluffy.yml
@@ -110,7 +110,7 @@ jobs:
         include:
           - target:
               os: linux
-            builder: ubuntu-18.04
+            builder: ubuntu-20.04
             shell: bash
           - target:
               os: macos
diff --git a/fluffy/fluffy.nim b/fluffy/fluffy.nim
index 92984e8dd..997287d06 100644
--- a/fluffy/fluffy.nim
+++ b/fluffy/fluffy.nim
@@ -118,6 +118,8 @@ proc run(config: PortalConf) {.raises: [CatchableError, Defect].} =
       registerIncomingSocketCallback(@[
         stateNetwork.portalProtocol.stream,
         historyNetwork.portalProtocol.stream]),
+      # for now we do not use user data in callbacks
+      nil,
       allowRegisteredIdCallback(@[
         stateNetwork.portalProtocol.stream,
         historyNetwork.portalProtocol.stream]),
diff --git a/fluffy/tests/test_history_network.nim b/fluffy/tests/test_history_network.nim
index 74e5de7ec..74c80a75f 100644
--- a/fluffy/tests/test_history_network.nim
+++ b/fluffy/tests/test_history_network.nim
@@ -34,6 +34,7 @@ proc newHistoryNode(rng: ref HmacDrbgContext, port: int): HistoryNode =
       node,
       utpProtocolId,
       registerIncomingSocketCallback(@[hn.portalProtocol.stream]),
+      nil,
       allowRegisteredIdCallback(@[hn.portalProtocol.stream]),
       socketConfig
     )
diff --git a/fluffy/tests/test_portal_wire_protocol.nim b/fluffy/tests/test_portal_wire_protocol.nim
index a133801da..d883a9234 100644
--- a/fluffy/tests/test_portal_wire_protocol.nim
+++ b/fluffy/tests/test_portal_wire_protocol.nim
@@ -51,6 +51,7 @@ proc initPortalProtocol(
     streamTransport = UtpDiscv5Protocol.new(
       d, utpProtocolId,
       registerIncomingSocketCallback(@[proto.stream]),
+      nil,
       allowRegisteredIdCallback(@[proto.stream]),
       socketConfig)
 
diff --git a/fluffy/tools/eth_data_exporter.nim b/fluffy/tools/eth_data_exporter.nim
index 75f2ec219..8177f58e3 100644
--- a/fluffy/tools/eth_data_exporter.nim
+++ b/fluffy/tools/eth_data_exporter.nim
@@ -64,7 +64,7 @@ proc defaultDataDir*(): string =
 
 const
   defaultDataDirDesc = defaultDataDir()
-  defaultBlockFileName = "eth-block-data.json"
+  defaultBlockFileName = "eth-block-data"
   defaultAccumulatorFileName = "eth-accumulator.json"
 
 type
diff --git a/fluffy/tools/portalcli.nim b/fluffy/tools/portalcli.nim
index 8181b075a..316cf7e3e 100644
--- a/fluffy/tools/portalcli.nim
+++ b/fluffy/tools/portalcli.nim
@@ -240,6 +240,7 @@ proc run(config: PortalCliConf) =
       d,
       utpProtocolId,
       registerIncomingSocketCallback(@[portal.stream]),
+      nil,
       allowRegisteredIdCallback(@[portal.stream]), socketConfig)
 
   setTransport(portal.stream, streamTransport)
diff --git a/vendor/nim-eth b/vendor/nim-eth
index 883825aad..2556b090e 160000
--- a/vendor/nim-eth
+++ b/vendor/nim-eth
@@ -1 +1 @@
-Subproject commit 883825aad78f5db6f24257e64c1441ae7f3a1d21
+Subproject commit 2556b090ea78416410098172b1ad3cc4d21a6474