diff --git a/core/src/main/kotlin/net/corda/core/transactions/SignedTransaction.kt b/core/src/main/kotlin/net/corda/core/transactions/SignedTransaction.kt
index 1d25d5e4fb..7da67105f1 100644
--- a/core/src/main/kotlin/net/corda/core/transactions/SignedTransaction.kt
+++ b/core/src/main/kotlin/net/corda/core/transactions/SignedTransaction.kt
@@ -30,6 +30,7 @@ import java.util.function.Predicate
  * sign.
  */
 // DOCSTART 1
+@CordaSerializable
 data class SignedTransaction(val txBits: SerializedBytes<CoreTransaction>,
                              override val sigs: List<TransactionSignature>
 ) : TransactionWithSignatures {
diff --git a/core/src/test/kotlin/net/corda/core/utilities/KotlinUtilsTest.kt b/core/src/test/kotlin/net/corda/core/utilities/KotlinUtilsTest.kt
index ae4a67c093..60bfdd8369 100644
--- a/core/src/test/kotlin/net/corda/core/utilities/KotlinUtilsTest.kt
+++ b/core/src/test/kotlin/net/corda/core/utilities/KotlinUtilsTest.kt
@@ -52,8 +52,7 @@ class KotlinUtilsTest : TestDependencyInjectionBase() {
     }
 
     @CordaSerializable
-    private class CapturingTransientProperty(prefix: String) {
-        private val seed = random63BitValue()
+    private class CapturingTransientProperty(val prefix: String, val seed: Long = random63BitValue()) {
         val transientVal by transient { prefix + seed + random63BitValue() }
     }
 }
\ No newline at end of file