diff --git a/component/dns/response_routing.go b/component/dns/response_routing.go
index 83a6f22b2a..25382cda26 100644
--- a/component/dns/response_routing.go
+++ b/component/dns/response_routing.go
@@ -9,7 +9,6 @@ import (
 	"fmt"
 	"net/netip"
 	"strconv"
-	"strings"
 
 	"github.com/daeuniverse/dae/common/consts"
 	"github.com/daeuniverse/dae/component/routing"
@@ -225,7 +224,6 @@ func (m *ResponseMatcher) Match(
 	if qName == "" {
 		return 0, fmt.Errorf("qName cannot be empty")
 	}
-	qName = strings.TrimSuffix(strings.ToLower(qName), ".")
 	domainMatchBitmap := m.domainMatcher.MatchDomainBitmap(qName)
 	bin128 := make([]string, 0, len(ips))
 	for _, ip := range ips {
diff --git a/component/routing/domain_matcher/ahocorasick_slimtrie.go b/component/routing/domain_matcher/ahocorasick_slimtrie.go
index 3f9fc785d1..dd9b908ba3 100644
--- a/component/routing/domain_matcher/ahocorasick_slimtrie.go
+++ b/component/routing/domain_matcher/ahocorasick_slimtrie.go
@@ -7,15 +7,16 @@ package domain_matcher
 
 import (
 	"fmt"
+	"regexp"
+	"strings"
+
 	"github.com/daeuniverse/dae/common/consts"
 	"github.com/daeuniverse/dae/pkg/trie"
 	"github.com/sirupsen/logrus"
 	"github.com/v2rayA/ahocorasick-domain"
-	"regexp"
-	"strings"
 )
 
-var ValidDomainChars = trie.NewValidChars([]byte("0123456789abcdefghijklmnopqrstuvwxyz-.^"))
+var ValidDomainChars = trie.NewValidChars([]byte("0123456789abcdefghijklmnopqrstuvwxyz-.^_"))
 
 type AhocorasickSlimtrie struct {
 	log *logrus.Logger
@@ -52,7 +53,7 @@ nextPattern:
 		case consts.RoutingDomainKey_Full:
 			for _, r := range []byte(d) {
 				if !ValidDomainChars.IsValidChar(r) {
-					n.log.Warnf("DomainMatcher: skip bad full domain: %v: unexpected chat: %v", d, r)
+					n.log.Warnf("DomainMatcher: skip bad full domain: %v: unexpected char: %v", d, string(r))
 					continue nextPattern
 				}
 			}
@@ -60,7 +61,7 @@ nextPattern:
 		case consts.RoutingDomainKey_Suffix:
 			for _, r := range []byte(d) {
 				if !ValidDomainChars.IsValidChar(r) {
-					n.log.Warnf("DomainMatcher: skip bad suffix domain: %v: unexpected chat: %v", d, r)
+					n.log.Warnf("DomainMatcher: skip bad suffix domain: %v: unexpected char: %v", d, string(r))
 					continue nextPattern
 				}
 			}
diff --git a/pkg/trie/trie_test.go b/pkg/trie/trie_test.go
index 408ca7cd95..d9e5697c7d 100644
--- a/pkg/trie/trie_test.go
+++ b/pkg/trie/trie_test.go
@@ -94,7 +94,8 @@ func TestTrie(t *testing.T) {
 		"zib.fmc^",
 		"zk.ytamlacbci.",
 		"zk.ytamlacbci^",
-	}, NewValidChars([]byte("0123456789abcdefghijklmnopqrstuvwxyz-.^")))
+		"nc.ude.ctsu.srorrim.pct_.sptth_", // https://github.com/daeuniverse/daed/issues/400
+	}, NewValidChars([]byte("0123456789abcdefghijklmnopqrstuvwxyz-.^_")))
 	if err != nil {
 		t.Fatal(err)
 	}