diff --git a/testkit/src/main/scala/org/bitcoins/testkit/async/TestAsyncUtil.scala b/testkit/src/main/scala/org/bitcoins/testkit/async/TestAsyncUtil.scala
index ad0fdf0874..c894a85999 100644
--- a/testkit/src/main/scala/org/bitcoins/testkit/async/TestAsyncUtil.scala
+++ b/testkit/src/main/scala/org/bitcoins/testkit/async/TestAsyncUtil.scala
@@ -6,7 +6,9 @@ import org.scalatest.exceptions.{StackDepthException, TestFailedException}
 import scala.concurrent.{ExecutionContext, Future}
 import scala.concurrent.duration.FiniteDuration
 
-abstract class TestAsyncUtil extends org.bitcoins.rpc.util.AsyncUtil {
+abstract class TestAsyncUtil
+    extends org.bitcoins.rpc.util.AsyncUtil
+    with Serializable {
   override protected def retryUntilSatisfiedWithCounter(
       conditionF: () => Future[Boolean],
       duration: FiniteDuration,