diff --git a/modules/route-proxy/cmd/route-proxy/routes_test.go b/modules/route-proxy/cmd/route-proxy/routes_test.go
index 58618fc..c92b9fc 100644
--- a/modules/route-proxy/cmd/route-proxy/routes_test.go
+++ b/modules/route-proxy/cmd/route-proxy/routes_test.go
@@ -172,7 +172,8 @@ func TestAPlanEntryIsDialledAtTheMachinePortItCarries(t *testing.T) {
 		{"on another machine, a bare port (influxdb)", "home", "influxdb", "home.internal", 8086, "http://home.internal:8086"},
 	} {
 		values, _ := json.Marshal(map[string]any{"name": c.module + ".example.org", "port": c.port})
-		contributed, err := catalogue.EncodeContributed(catalogue.ContributedForm{At: c.at,
+		// The form as the seat carries it (version 1): written here, so what the proxy decodes is the shape, not a helper.
+		contributed, err := json.Marshal(catalogue.ContributedForm{V: catalogue.ContributedVersion, At: c.at,
 			Each: []catalogue.ContributedOne{{Values: values}}})
 		if err != nil {
 			t.Fatalf("%s: %v", c.name, err)