diff --git a/infra/conf/common.go b/infra/conf/common.go
index cc439c3dd..b97a200ac 100644
--- a/infra/conf/common.go
+++ b/infra/conf/common.go
@@ -195,8 +195,11 @@ func (list *PortList) Build() *net.PortList {
 // UnmarshalJSON implements encoding/json.Unmarshaler.UnmarshalJSON
 func (list *PortList) UnmarshalJSON(data []byte) error {
 	var listStr string
+	var number uint32
 	if err := json.Unmarshal(data, &listStr); err != nil {
-		return newError("invalid port list: ", string(data)).Base(err)
+		if err2 := json.Unmarshal(data, &number); err2 != nil {
+			return newError("invalid port: ", string(data)).Base(err2)
+		}
 	}
 	rangelist := strings.Split(listStr, ",")
 	for _, rangeStr := range rangelist {
@@ -217,6 +220,9 @@ func (list *PortList) UnmarshalJSON(data []byte) error {
 			}
 		}
 	}
+	if number != 0 {
+		list.Range = append(list.Range, PortRange{From: uint32(number), To: uint32(number)})
+	}
 	return nil
 }
 
diff --git a/infra/conf/router_test.go b/infra/conf/router_test.go
index 52676ad25..ac4284dc8 100644
--- a/infra/conf/router_test.go
+++ b/infra/conf/router_test.go
@@ -48,6 +48,10 @@ func TestRouterConfig(t *testing.T) {
 							"type": "field",
 							"port": "53, 443, 1000-2000",
 							"outboundTag": "test"
+						},{
+							"type": "field",
+							"port": 123,
+							"outboundTag": "test"
 						}
 					]
 				},
@@ -114,6 +118,16 @@ func TestRouterConfig(t *testing.T) {
 							Tag: "test",
 						},
 					},
+					{
+						PortList: &net.PortList{
+							Range: []*net.PortRange{
+								{From: 123, To: 123},
+							},
+						},
+						TargetTag: &router.RoutingRule_Tag{
+							Tag: "test",
+						},
+					},
 				},
 			},
 		},