diff --git a/lib/autoupdate/rollout/controller.go b/lib/autoupdate/rollout/controller.go
index f80c9b168c221..8f05e2c45ccca 100644
--- a/lib/autoupdate/rollout/controller.go
+++ b/lib/autoupdate/rollout/controller.go
@@ -64,7 +64,7 @@ func NewController(client Client, log *slog.Logger, clock clockwork.Clock, perio
 		return nil, trace.BadParameter("missing clock")
 	}
 	if reg == nil {
-		reg = prometheus.DefaultRegisterer
+		return nil, trace.BadParameter("missing prometheus.Registerer")
 	}
 
 	if period <= 0 {