diff --git a/go/buscompose/names_test.go b/go/buscompose/names_test.go
index 25934e2..6f4bd17 100644
--- a/go/buscompose/names_test.go
+++ b/go/buscompose/names_test.go
@@ -4,7 +4,12 @@ import (
 	"strings"
 	"testing"
 
+	"git.novox.be/novox/mesh-contracts/go/seats/containerimageregistry"
+	"git.novox.be/novox/mesh-contracts/go/seats/gopackageregistry"
 	"git.novox.be/novox/mesh-contracts/go/seats/meshbroker"
+	"git.novox.be/novox/mesh-contracts/go/seats/npmpackageregistry"
+	"git.novox.be/novox/mesh-contracts/go/seats/ociartifactregistry"
+	"git.novox.be/novox/mesh-contracts/go/seats/operatorchannel"
 	"git.novox.be/novox/mesh-sdk/go/membership"
 )
 
@@ -43,6 +48,17 @@ func TestTheBusNamesAgree(t *testing.T) {
 			}
 		}
 	}
+	// A seat family on the shared events stream is kept as long as the stream keeps it: its contract says no more.
+	for family, days := range map[string]int{operatorchannel.Family: operatorchannel.FamilyMaxAgeDays,
+		npmpackageregistry.Family: npmpackageregistry.FamilyMaxAgeDays, gopackageregistry.Family: gopackageregistry.FamilyMaxAgeDays,
+		containerimageregistry.Family: containerimageregistry.FamilyMaxAgeDays,
+		ociartifactregistry.Family:    ociartifactregistry.FamilyMaxAgeDays} {
+		for _, st := range MeshStreams() {
+			if st.Name == EventsStream && int64(days)*24*60*60 != int64(st.MaxAge) {
+				t.Errorf("the family %s says %d days, the shared events stream keeps %d s", family, days, st.MaxAge)
+			}
+		}
+	}
 }
 
 // subjectTakes says whether a subject pattern (`*` one token, `>` the rest) takes a subject.