diff --git a/src/commonMain/kotlin/net/sergeych/kiloparsec/KiloParams.kt b/src/commonMain/kotlin/net/sergeych/kiloparsec/KiloParams.kt
index 7d29ca3..9b3ff33 100644
--- a/src/commonMain/kotlin/net/sergeych/kiloparsec/KiloParams.kt
+++ b/src/commonMain/kotlin/net/sergeych/kiloparsec/KiloParams.kt
@@ -3,6 +3,7 @@ package net.sergeych.kiloparsec
 import kotlinx.serialization.Serializable
 import net.sergeych.bintools.toDataSource
 import net.sergeych.bipack.BipackDecoder
+import net.sergeych.bipack.Unsigned
 import net.sergeych.crypto2.*
 import net.sergeych.synctools.ProtectedOp
 import net.sergeych.synctools.invoke
@@ -28,6 +29,7 @@ data class KiloParams<S>(
 ) {
     @Serializable
     data class Package(
+        @Unsigned
         val nonce: ULong,
         val encryptedMessage: UByteArray,
     )
diff --git a/src/commonTest/kotlin/PackTest.kt b/src/commonTest/kotlin/PackTest.kt
index 1495c06..7af9197 100644
--- a/src/commonTest/kotlin/PackTest.kt
+++ b/src/commonTest/kotlin/PackTest.kt
@@ -1,11 +1,15 @@
+import kotlinx.coroutines.runBlocking
 import kotlinx.coroutines.test.runTest
 import kotlinx.datetime.Instant
+import net.sergeych.bipack.BipackEncoder
 import net.sergeych.crypto2.initCrypto
+import net.sergeych.kiloparsec.KiloParams
 import net.sergeych.kiloparsec.Transport
 import net.sergeych.utools.nowToSeconds
 import net.sergeych.utools.pack
 import net.sergeych.utools.unpack
 import kotlin.test.Test
+import kotlin.test.assertContentEquals
 import kotlin.test.assertEquals
 import kotlin.time.Duration.Companion.microseconds
 
@@ -40,4 +44,10 @@ class PackTest {
         val b2 = unpack<Transport.Block>(p1)
         assertEquals(b1,b2)
     }
+
+    @Test
+    fun packPackage() = runBlocking {
+        val x = BipackEncoder.encode(KiloParams.Package(1u, ubyteArrayOf()))
+        assertContentEquals(byteArrayOf(4, 0), x)
+    }
 }
\ No newline at end of file