diff --git a/pkg/network/csn.go b/pkg/network/csn.go
index d095d33eb..a89271dfd 100644
--- a/pkg/network/csn.go
+++ b/pkg/network/csn.go
@@ -42,7 +42,9 @@ type InterfaceDescription struct {
 	// namespace or to control file in sysfs for sr-iov VF.
 	// It may be nil if the interface was recovered after restarting Virtlet.
 	// It's only needed during the initial VM startup.
-	Fo *os.File
+	// The json tag is here so that bogus File object doesn't get stored
+	// in the metadata db.
+	Fo *os.File `json:"-"`
 	// Name contains original interface name for sr-iov interface.
 	Name string
 	// HardwareAddr contains original hardware address for CNI-created