diff --git a/go/oasis-test-runner/oasis/client.go b/go/oasis-test-runner/oasis/client.go
index 7e2e98a9d11..4d785e63e36 100644
--- a/go/oasis-test-runner/oasis/client.go
+++ b/go/oasis-test-runner/oasis/client.go
@@ -58,6 +58,11 @@ func (client *Client) ModifyConfig() error {
 
 	client.Config.P2P.Port = client.p2pPort
 
+	if !client.entity.isDebugTestEntity {
+		entityID, _ := client.entity.ID().MarshalText() // Cannot fail.
+		client.Config.Registration.EntityID = string(entityID)
+	}
+
 	if len(client.runtimes) > 0 {
 		client.Config.Mode = config.ModeClient
 		client.Config.Runtime.Provisioner = client.runtimeProvisioner