diff --git a/codexvalidator/blocks/blck.nim b/codexvalidator/blocks/blck.nim
index c457e5f..2fef01c 100644
--- a/codexvalidator/blocks/blck.nim
+++ b/codexvalidator/blocks/blck.nim
@@ -2,6 +2,7 @@ from pkg/mysticeti import CommitteeMember, `==`, `$`
 import ../basics
 import ../transaction
 import ../hashing
+import ../signatures
 import ./blockid
 
 export mysticeti.CommitteeMember
@@ -12,7 +13,7 @@ type Block* = ref object
   author*: CommitteeMember
   round*: uint64
   parents*: seq[BlockId]
-  transactions*: seq[Transaction]
+  transactions*: seq[Signed[Transaction]]
   hash: ?Hash
 
 func `hash=`*(blck: Block, hash: Hash) =
diff --git a/codexvalidator/blocks/deserialization.nim b/codexvalidator/blocks/deserialization.nim
index 75073b4..d7a48b2 100644
--- a/codexvalidator/blocks/deserialization.nim
+++ b/codexvalidator/blocks/deserialization.nim
@@ -25,7 +25,7 @@ func init*(
     author: CommitteeMember(message.author),
     round: message.round,
     parents: message.parents.mapIt(? BlockId.init(it)),
-    transactions: message.transactions.mapIt(? Transaction.init(it))
+    transactions: message.transactions.mapIt(? Signed[Transaction].init(it))
   )
 
 func init*(
diff --git a/codexvalidator/blocks/serialization.nim b/codexvalidator/blocks/serialization.nim
index ee5215c..48a5532 100644
--- a/codexvalidator/blocks/serialization.nim
+++ b/codexvalidator/blocks/serialization.nim
@@ -28,14 +28,14 @@ type BlockMessage* {.proto3.} = object
   author* {.fieldNumber: 1, pint.}: uint32
   round* {.fieldNumber: 2, pint.}: uint64
   parents* {.fieldNumber: 3.}: seq[BlockIdMessage]
-  transactions* {.fieldNumber: 4.}: seq[TransactionMessage]
+  transactions* {.fieldNumber: 4.}: seq[SignedTransactionMessage]
 
 func init*(_: type BlockMessage, blck: Block): BlockMessage =
   BlockMessage(
     author: blck.author.uint32,
     round: blck.round,
     parents: blck.parents.mapIt(BlockIdMessage.init(it)),
-    transactions: blck.transactions.mapIt(TransactionMessage.init(it))
+    transactions: blck.transactions.mapIt(SignedTransactionMessage.init(it))
   )
 
 func toBytes*(blck: Block): seq[byte] =
diff --git a/codexvalidator/transaction/deserialization.nim b/codexvalidator/transaction/deserialization.nim
index 7c35696..b397b89 100644
--- a/codexvalidator/transaction/deserialization.nim
+++ b/codexvalidator/transaction/deserialization.nim
@@ -55,7 +55,7 @@ func init(_: type Groth16Proof, message: Groth16ProofMessage): Groth16Proof =
     )
   )
 
-func init*(_: type Transaction, message: TransactionMessage): ?!Transaction =
+func init(_: type Transaction, message: TransactionMessage): ?!Transaction =
   if message.version != TransactionVersion.version0.uint32:
     return failure "unsupported transaction version: " & $message.version
   let proofInput = ? StorageProofInput.init(message.proofInput)
@@ -68,7 +68,7 @@ func init*(_: type Transaction, message: TransactionMessage): ?!Transaction =
   else:
     failure "invalid transaction kind: " & $message.kind
 
-func init(
+func init*(
   _: type Signed[Transaction],
   message: SignedTransactionMessage
 ): ?!Signed[Transaction] =
diff --git a/tests/codexvalidator/blocks/testSerialization.nim b/tests/codexvalidator/blocks/testSerialization.nim
index 107a449..3b8d47a 100644
--- a/tests/codexvalidator/blocks/testSerialization.nim
+++ b/tests/codexvalidator/blocks/testSerialization.nim
@@ -25,7 +25,7 @@ suite "Block serialization":
     check protobuf.author == blck.author.uint32
     check protobuf.round == blck.round
     check protobuf.parents == blck.parents.mapIt(BlockIdMessage.init(it))
-    check protobuf.transactions == blck.transactions.mapIt(TransactionMessage.init(it))
+    check protobuf.transactions == blck.transactions.mapIt(SignedTransactionMessage.init(it))
 
   test "serializes a signed block with protobuf":
     let blck = Block.example
@@ -79,8 +79,8 @@ suite "Block serialization":
   test "deserialization fails when transaction is invalid":
     let signed = Signed[Block].example
     var message = SignedBlockMessage.init(signed)
-    var transaction = TransactionMessage.init(Transaction.example)
-    transaction.version = 42'u8
+    var transaction = SignedTransactionMessage.init(Signed[Transaction].example)
+    transaction.transaction.version = 42'u8
     message.blck.transactions &= transaction
     let invalid = Protobuf.encode(message)
     let deserialized = Signed[Block].fromBytes(invalid)
diff --git a/tests/codexvalidator/examples.nim b/tests/codexvalidator/examples.nim
index 6736b83..c3ce821 100644
--- a/tests/codexvalidator/examples.nim
+++ b/tests/codexvalidator/examples.nim
@@ -94,5 +94,5 @@ proc example*(_: type Block): Block =
     author: CommitteeMember.example,
     round: uint64.example,
     parents: seq[BlockId].example,
-    transactions: seq[Transaction].example
+    transactions: seq[Signed[Transaction]].example
   )