diff --git a/client/src/components/Settings/Dns/Cache/Form.js b/client/src/components/Settings/Dns/Cache/Form.js
index 0f51e117246..c772019f099 100644
--- a/client/src/components/Settings/Dns/Cache/Form.js
+++ b/client/src/components/Settings/Dns/Cache/Form.js
@@ -41,7 +41,7 @@ const Form = ({
         cache_ttl_max, cache_ttl_min,
     } = useSelector((state) => state.form[FORM_NAME.CACHE].values, shallowEqual);
 
-    const minExceedsMax = cache_ttl_min > cache_ttl_max;
+    const minExceedsMax = cache_ttl_min > 0 && cache_ttl_max > 0 && cache_ttl_min > cache_ttl_max;
 
     const handleClearCache = () => {
         if (window.confirm(t('confirm_dns_cache_clear'))) {
diff --git a/internal/dnsforward/http.go b/internal/dnsforward/http.go
index ac82ea76f9f..1e628278099 100644
--- a/internal/dnsforward/http.go
+++ b/internal/dnsforward/http.go
@@ -346,23 +346,24 @@ func (req *jsonDNSConfig) validateUpstreamDNSServers(privateNets netutil.SubnetS
 // checkCacheTTL returns an error if the configuration of the cache TTL is
 // invalid.
 func (req *jsonDNSConfig) checkCacheTTL() (err error) {
-	if req.CacheMinTTL == nil && req.CacheMaxTTL == nil {
+	if req.CacheMinTTL == nil || req.CacheMaxTTL == nil {
 		return nil
 	}
 
-	var minTTL, maxTTL uint32
-	if req.CacheMinTTL != nil {
+	var (
 		minTTL = *req.CacheMinTTL
-	}
-	if req.CacheMaxTTL != nil {
 		maxTTL = *req.CacheMaxTTL
-	}
+	)
 
-	if minTTL <= maxTTL {
+	if minTTL == 0 || maxTTL == 0 {
 		return nil
 	}
 
-	return errors.Error("cache_ttl_min must be less or equal than cache_ttl_max")
+	if minTTL > maxTTL {
+		return errors.Error("cache_ttl_min must be less or equal than cache_ttl_max")
+	}
+
+	return nil
 }
 
 // checkRatelimitSubnetMaskLen returns an error if the length of the subnet mask