diff --git a/dns/enhancer.go b/dns/enhancer.go
index 16ae020..faaa072 100644
--- a/dns/enhancer.go
+++ b/dns/enhancer.go
@@ -78,7 +78,7 @@ func NewEnhancer(cfg Config) *ResolverEnhancer {
 
 	if cfg.EnhancedMode != C.DNSNormal {
 		fakePool = cfg.Pool
-		mapping = cache.New(cache.WithSize(4096), cache.WithStale(true))
+		mapping = cache.New(cache.WithSize(4096))
 	}
 
 	return &ResolverEnhancer{
diff --git a/dns/middleware.go b/dns/middleware.go
index deb8015..7ec2890 100644
--- a/dns/middleware.go
+++ b/dns/middleware.go
@@ -100,6 +100,9 @@ func withMapping(mapping *cache.LruCache) middleware {
 					continue
 				}
 
+				if ttl < 1 {
+					ttl = 1
+				}
 				mapping.SetWithExpire(ip.String(), host, time.Now().Add(time.Second*time.Duration(ttl)))
 			}