diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 1d1881b..708f8c5 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -237,3 +237,4 @@ jobs:
           nimble install -y --depsOnly
           nimble test
           nimble build_dcli
+          nimble build_fuzzers
diff --git a/eth.nimble b/eth.nimble
index 50e1f42..85d801a 100644
--- a/eth.nimble
+++ b/eth.nimble
@@ -90,3 +90,16 @@ task test_discv5_full, "Run discovery v5 and its dependencies tests":
 
 task build_dcli, "Build dcli":
   buildBinary("eth/p2p/discoveryv5/dcli")
+
+import os, strutils
+
+task build_fuzzers, "Build fuzzer test cases":
+  # This file is there to be able to quickly build the fuzzer test cases in
+  # order to avoid bit rot (e.g. for CI). Not for actual fuzzing.
+  # TODO: Building fuzzer test case one by one will make it take a bit longer,
+  # but we cannot import them in one Nim file due to the usage of
+  # `exportc: "AFLmain"` in the fuzzing test template for Windows:
+  # https://github.com/status-im/nim-testutils/blob/master/testutils/fuzzing.nim#L100
+  for file in walkDirRec("tests/fuzzing/"):
+    if file.endsWith("nim"):
+      buildBinary(file)
diff --git a/eth/p2p/blockchain_utils.nim b/eth/p2p/blockchain_utils.nim
index 0caf9e3..064de96 100644
--- a/eth/p2p/blockchain_utils.nim
+++ b/eth/p2p/blockchain_utils.nim
@@ -6,7 +6,7 @@
 # at your option. This file may not be copied, modified, or distributed except according to those terms.
 
 import
-  eth/common/[eth_types, state_accessors]
+  ../common/[eth_types, state_accessors]
 
 # TODO: Perhaps we can move this to eth-common
 
diff --git a/tests/fuzzing/discovery/fuzz.nim b/tests/fuzzing/discovery/fuzz.nim
index 35b8a11..8d816ed 100644
--- a/tests/fuzzing/discovery/fuzz.nim
+++ b/tests/fuzzing/discovery/fuzz.nim
@@ -1,11 +1,18 @@
 import
-  testutils/fuzzing, chronicles,
-  eth/p2p/[discovery, enode], eth/[keys, rlp],
+  testutils/fuzzing, chronicles, nimcrypto/keccak,
+  ../../../eth/p2p/[discovery, enode], ../../../eth/[keys, rlp],
   ../../p2p/p2p_test_helper
 
 const DefaultListeningPort = 30303
 var targetNode: DiscoveryProtocol
 
+proc packData(payload: openArray[byte], pk: PrivateKey): seq[byte] =
+  let
+    payloadSeq = @payload
+    signature = @(pk.sign(payload).toRaw())
+    msgHash = keccak256.digest(signature & payloadSeq)
+  result = @(msgHash.data) & signature & payloadSeq
+
 init:
   # Set up a discovery node, this is the node we target when fuzzing
   var
diff --git a/tests/fuzzing/discovery/generate.nim b/tests/fuzzing/discovery/generate.nim
index f0c1911..c51bc72 100644
--- a/tests/fuzzing/discovery/generate.nim
+++ b/tests/fuzzing/discovery/generate.nim
@@ -1,17 +1,13 @@
 import
-  chronos, times, stew/byteutils, stint, chronicles, streams, nimcrypto, os,
-  strformat, strutils, eth/p2p/[discovery, kademlia], eth/[keys, rlp],
-  ../../p2p/p2p_test_helper
+  std/[times, os, strformat, strutils],
+  chronos, stew/byteutils, stint, chronicles, nimcrypto,
+  ../../../eth/p2p/[discovery, kademlia], ../../../eth/[keys, rlp],
+  ../../p2p/p2p_test_helper,
+  ../fuzzing_helpers
 
 template sourceDir: string = currentSourcePath.rsplit(DirSep, 1)[0]
 const inputsDir = &"{sourceDir}{DirSep}generated-input{DirSep}"
 
-proc toFile(data: Bytes, fn: string) =
-  var s = newFileStream(fn, fmWrite)
-  for x in data:
-    s.write(x)
-  s.close()
-
 const EXPIRATION = 3600 * 24 * 365 * 10
 proc expiration(): uint32 = uint32(epochTime() + EXPIRATION)
 
@@ -32,7 +28,7 @@ proc generate() =
 
   # valid data for a Pong packet
   block:
-    let token = keccak256.digest(@[0])
+    let token = keccak256.digest(@[byte 0])
     let payload = rlp.encode((toAddr, token , expiration()))
     let encodedData = @[2.byte] & payload
     debug "Pong", data=byteutils.toHex(encodedData)
@@ -42,9 +38,9 @@ proc generate() =
   # valid data for a FindNode packet
   block:
     var data: array[64, byte]
-    data[32 .. ^1] = peerKey.toPublicKey().tryGet().toNodeId().toByteArrayBE()
+    data[32 .. ^1] = peerKey.toPublicKey().toNodeId().toByteArrayBE()
     let payload = rlp.encode((data, expiration()))
-    let encodedData = @[3.byte] & payload.toSeq()
+    let encodedData = @[3.byte] & @payload
     debug "FindNode", data=byteutils.toHex(encodedData)
 
     encodedData.toFile(inputsDir & "findnode")
@@ -62,11 +58,11 @@ proc generate() =
     type Neighbour = tuple[ip: IpAddress, udpPort, tcpPort: Port, pk: PublicKey]
     var nodes = newSeqOfCap[Neighbour](2)
 
-    nodes.add((n1Addr.ip, n1Addr.udpPort, n1Addr.tcpPort, n1Key.toPublicKey().tryGet()))
-    nodes.add((n2Addr.ip, n2Addr.udpPort, n2Addr.tcpPort, n2Key.toPublicKey().tryGet()))
+    nodes.add((n1Addr.ip, n1Addr.udpPort, n1Addr.tcpPort, n1Key.toPublicKey()))
+    nodes.add((n2Addr.ip, n2Addr.udpPort, n2Addr.tcpPort, n2Key.toPublicKey()))
 
     let payload = rlp.encode((nodes, expiration()))
-    let encodedData = @[4.byte] & payload.toSeq()
+    let encodedData = @[4.byte] & @payload
     debug "Neighbours", data=byteutils.toHex(encodedData)
 
     encodedData.toFile(inputsDir & "neighbours")
diff --git a/tests/fuzzing/discoveryv5/fuzz_decode_message.nim b/tests/fuzzing/discoveryv5/fuzz_decode_message.nim
index 5f8de42..e9ca520 100644
--- a/tests/fuzzing/discoveryv5/fuzz_decode_message.nim
+++ b/tests/fuzzing/discoveryv5/fuzz_decode_message.nim
@@ -1,6 +1,6 @@
 import
-  testutils/fuzzing, stew/byteutils,
-  eth/rlp, eth/p2p/discoveryv5/[encoding, messages]
+  testutils/fuzzing,
+  ../../../eth/rlp, ../../../eth/p2p/discoveryv5/[encoding, messages]
 
 test:
   block:
diff --git a/tests/fuzzing/discoveryv5/fuzz_decode_packet.nim b/tests/fuzzing/discoveryv5/fuzz_decode_packet.nim
index 4be0be7..c320f4c 100644
--- a/tests/fuzzing/discoveryv5/fuzz_decode_packet.nim
+++ b/tests/fuzzing/discoveryv5/fuzz_decode_packet.nim
@@ -1,6 +1,6 @@
 import
-  testutils/fuzzing, stew/shims/net, stew/byteutils,
-  eth/p2p/discoveryv5/[encoding, enr, sessions, node]
+  testutils/fuzzing, stew/shims/net,
+  ../../../eth/p2p/discoveryv5/[encoding, enr, sessions, node]
 
 init:
   const
diff --git a/tests/fuzzing/enr/fuzz_enr.nim b/tests/fuzzing/enr/fuzz_enr.nim
index e17a844..2c56d9f 100644
--- a/tests/fuzzing/enr/fuzz_enr.nim
+++ b/tests/fuzzing/enr/fuzz_enr.nim
@@ -1,6 +1,6 @@
 import
   testutils/fuzzing, stew/byteutils,
-  eth/rlp, eth/p2p/discoveryv5/enr
+  ../../../eth/rlp, ../../../eth/p2p/discoveryv5/enr
 
 test:
   block:
diff --git a/tests/fuzzing/enr/generate.nim b/tests/fuzzing/enr/generate.nim
index f39b4d5..c2c3131 100644
--- a/tests/fuzzing/enr/generate.nim
+++ b/tests/fuzzing/enr/generate.nim
@@ -1,7 +1,7 @@
 import
   std/[os, strutils, options],
   stew/shims/net,
-  eth/keys, eth/p2p/discoveryv5/enr,
+  ../../../eth/keys, ../../../eth/p2p/discoveryv5/enr,
   ../fuzzing_helpers
 
 template sourceDir: string = currentSourcePath.rsplit(DirSep, 1)[0]
@@ -12,7 +12,7 @@ proc generate() =
     rng = newRng()
     privKey = PrivateKey.random(rng[])
     ip = some(ValidIpAddress.init("127.0.0.1"))
-    port = Port(20301)
+    port = some(Port(20301))
 
   block:
     let record = enr.Record.init(1, privKey, ip, port, port)[]
diff --git a/tests/fuzzing/fuzzing_helpers.nim b/tests/fuzzing/fuzzing_helpers.nim
index 1ba2700..dc9d8bd 100644
--- a/tests/fuzzing/fuzzing_helpers.nim
+++ b/tests/fuzzing/fuzzing_helpers.nim
@@ -1,5 +1,5 @@
 import
-    std/streams
+  std/streams
 
 proc toFile*(data: seq[byte], fn: string) =
   var s = newFileStream(fn, fmWrite)
diff --git a/tests/fuzzing/rlp/rlp_decode.nim b/tests/fuzzing/rlp/rlp_decode.nim
index 5b7d39e..83561b6 100644
--- a/tests/fuzzing/rlp/rlp_decode.nim
+++ b/tests/fuzzing/rlp/rlp_decode.nim
@@ -1,6 +1,6 @@
 import
   testutils/fuzzing, chronicles,
-  eth/rlp
+  ../../../eth/rlp
 
 type
   TestEnum = enum
diff --git a/tests/fuzzing/rlp/rlp_inspect.nim b/tests/fuzzing/rlp/rlp_inspect.nim
index 64c9657..fb2f266 100644
--- a/tests/fuzzing/rlp/rlp_inspect.nim
+++ b/tests/fuzzing/rlp/rlp_inspect.nim
@@ -1,6 +1,6 @@
 import
   testutils/fuzzing, chronicles,
-  eth/rlp
+  ../../../eth/rlp
 
 test:
   try:
diff --git a/tests/fuzzing/rlpx/thunk.nim b/tests/fuzzing/rlpx/thunk.nim
index d418ce4..c050acd 100644
--- a/tests/fuzzing/rlpx/thunk.nim
+++ b/tests/fuzzing/rlpx/thunk.nim
@@ -1,8 +1,8 @@
 import
   testutils/fuzzing, chronos,
-  eth/p2p, eth/p2p/rlpx, eth/p2p/private/p2p_types,
-  eth/p2p/rlpx_protocols/[whisper_protocol, eth_protocol],
-  ../p2p/p2p_test_helper
+  ../../../eth/p2p, ../../../eth/p2p/rlpx, ../../../eth/p2p/private/p2p_types,
+  ../../../eth/p2p/rlpx_protocols/[whisper_protocol, eth_protocol],
+  ../../p2p/p2p_test_helper
 
 var
   node1: EthereumNode
diff --git a/tests/fuzzing/whisper/encode_decode.nim b/tests/fuzzing/whisper/encode_decode.nim
index cc8004a..2a056d6 100644
--- a/tests/fuzzing/whisper/encode_decode.nim
+++ b/tests/fuzzing/whisper/encode_decode.nim
@@ -1,13 +1,15 @@
 import
-  options, sequtils, chronicles,
-  eth/p2p/rlpx_protocols/whisper_protocol as whisper,
-  ../fuzztest
+  std/[options, sequtils],
+  chronicles, testutils/fuzzing,
+  ../../../eth/p2p/rlpx_protocols/whisper_protocol as whisper,
+  ../../../eth/keys
 
 test:
   let
+    rng = newRng()
     data = @payload.distribute(2)
     whisperPayload = Payload(payload: data[0], padding: some(data[1]))
-    encoded = whisper.encode(whisperPayload)
+    encoded = whisper.encode(rng[], whisperPayload)
 
     decoded = whisper.decode(encoded.get())