diff --git a/pkg/sourcetransformer/examples/assign_event_time/main.go b/pkg/sourcetransformer/examples/assign_event_time/main.go
index b1b1a01b..d53c2326 100644
--- a/pkg/sourcetransformer/examples/assign_event_time/main.go
+++ b/pkg/sourcetransformer/examples/assign_event_time/main.go
@@ -15,6 +15,8 @@ type AssignEventTime struct {
 func (a *AssignEventTime) Transform(ctx context.Context, keys []string, d sourcetransformer.Datum) sourcetransformer.Messages {
 	// Update message event time to time.Now()
 	eventTime := time.Now()
+	// Log the action so that we can use it for testing.
+	log.Printf("AssignEventTime: Assigning event time %v to message %s", eventTime, string(d.Value()))
 	return sourcetransformer.MessagesBuilder().Append(sourcetransformer.NewMessage(d.Value(), eventTime).WithKeys(keys))
 }