diff --git a/libtailscale/backend.go b/libtailscale/backend.go
index 5c220059a1..35828086f3 100644
--- a/libtailscale/backend.go
+++ b/libtailscale/backend.go
@@ -336,6 +336,7 @@ func (a *App) newBackend(dataDir string, appCtx AppContext, store *stateStore,
 		DNS:            vf,
 		ReconfigureVPN: vf.ReconfigureVPN,
 		Dialer:         dialer,
+		ExtraRootCAs:   sys.ExtraRootCAs,
 		SetSubsystem:   sys.Set,
 		NetMon:         b.netMon,
 		HealthTracker:  sys.HealthTracker.Get(),