diff --git a/engine/mac_resolver.go b/engine/mac_resolver.go
index 7561462..cedda40 100644
--- a/engine/mac_resolver.go
+++ b/engine/mac_resolver.go
@@ -164,7 +164,7 @@ func (r *sourceMACResolver) refreshARPCache(now time.Time) {
 
 func (r *sourceMACResolver) refreshNDPCache(now time.Time) {
 	m, ok := readNeighborCacheFile("/proc/net/ndisc_cache")
-	if !ok {
+	if !ok || len(m) == 0 {
 		// Fallback for environments without /proc/net/ndisc_cache.
 		m = readIPv6NeighCommand()
 	}