diff --git a/net/dns/direct.go b/net/dns/direct.go
index dcf18e622..f42a83803 100644
--- a/net/dns/direct.go
+++ b/net/dns/direct.go
@@ -76,14 +76,6 @@ func readResolv(r io.Reader) (config OSConfig, err error) {
 	return config, nil
 }
 
-func (m directManager) readResolvFile(path string) (OSConfig, error) {
-	b, err := m.fs.ReadFile(path)
-	if err != nil {
-		return OSConfig{}, err
-	}
-	return readResolv(bytes.NewReader(b))
-}
-
 // resolvOwner returns the apparent owner of the resolv.conf
 // configuration in bs - one of "resolvconf", "systemd-resolved" or
 // "NetworkManager", or "" if no known owner was found.
@@ -152,6 +144,14 @@ func newDirectManagerOnFS(fs wholeFileFS) directManager {
 	return directManager{fs: fs}
 }
 
+func (m directManager) readResolvFile(path string) (OSConfig, error) {
+	b, err := m.fs.ReadFile(path)
+	if err != nil {
+		return OSConfig{}, err
+	}
+	return readResolv(bytes.NewReader(b))
+}
+
 // ownedByTailscale reports whether /etc/resolv.conf seems to be a
 // tailscale-managed file.
 func (m directManager) ownedByTailscale() (bool, error) {