diff --git a/nitro/channel.nim b/nitro/channel.nim
index c842cf8..5cc5809 100644
--- a/nitro/channel.nim
+++ b/nitro/channel.nim
@@ -12,7 +12,9 @@ type
 
 proc getChannelId*(channel: Channel): array[32, byte] =
   var writer: AbiWriter
+  writer.startTuple()
   writer.write(channel.chainId)
   writer.write(channel.participants)
   writer.write(channel.nonce)
+  writer.finishTuple()
   keccak256.digest(writer.finish()).data
diff --git a/tests/nitro/testChannel.nim b/tests/nitro/testChannel.nim
index 90f8906..29e7805 100644
--- a/tests/nitro/testChannel.nim
+++ b/tests/nitro/testChannel.nim
@@ -10,9 +10,11 @@ suite "channel":
 
   test "calculates channel id":
     var writer: AbiWriter
+    writer.startTuple()
     writer.write(channel.chainId)
     writer.write(channel.participants)
     writer.write(channel.nonce)
+    writer.finishTuple()
     let encoded = writer.finish()
     let hashed = keccak256.digest(encoded).data
     check getChannelId(channel) == hashed