diff --git a/testutil/src/main/java/tech/pegasys/orion/testutil/OrionTestHarness.java b/testutil/src/main/java/tech/pegasys/orion/testutil/OrionTestHarness.java
index ea35b656cf..d1cc4ac16b 100644
--- a/testutil/src/main/java/tech/pegasys/orion/testutil/OrionTestHarness.java
+++ b/testutil/src/main/java/tech/pegasys/orion/testutil/OrionTestHarness.java
@@ -51,9 +51,11 @@ public static OrionTestHarness create(final Path tempDir) throws Exception {
         "tls=\"off\"\n"
             + "tlsservertrust=\"tofu\"\n"
             + "tlsclienttrust=\"tofu\"\n"
+            + "nodeport=0\n"
             + "nodenetworkinterface = \""
             + HOST
             + "\"\n"
+            + "clientport=0\n"
             + "clientnetworkinterface = \""
             + HOST
             + "\"\n"