diff --git a/cmix/interface.go b/cmix/interface.go
index a8d5df5250ca67c37d7b01f30c4620787678538f..e293779740fa476c45815554388e7e2f94462e9f 100644
--- a/cmix/interface.go
+++ b/cmix/interface.go
@@ -192,7 +192,7 @@ type Client interface {
 		response message.Processor)
 
 	// ChangeParallelNodeRegistration .
-	ChangeParallelNodeRegistration(num int) stoppable.Single
+	ChangeParallelNodeRegistration(num int) func() (stoppable.Stoppable, error)
 
 	// DeleteService deletes a message service. If only a single response is
 	// associated with the preimage, the entire preimage is removed. If there is