diff --git a/sip/parse_uri_test.go b/sip/parse_uri_test.go
index 33a0fa5..4f54911 100644
--- a/sip/parse_uri_test.go
+++ b/sip/parse_uri_test.go
@@ -39,6 +39,7 @@ func TestParseUri(t *testing.T) {
 	})
 
 	t.Run("sip case insensitive", func(t *testing.T) {
+		uri = Uri{}
 		testCases := []string{
 			"sip:alice@atlanta.com",
 			"SIP:alice@atlanta.com",
@@ -50,6 +51,7 @@ func TestParseUri(t *testing.T) {
 			assert.Equal(t, "alice", uri.User)
 			assert.Equal(t, "atlanta.com", uri.Host)
 			assert.False(t, uri.IsEncrypted())
+			assert.Equal(t, "atlanta.com:5060", uri.HostPort())
 		}
 
 		testCases = []string{
@@ -63,6 +65,7 @@ func TestParseUri(t *testing.T) {
 			assert.Equal(t, "alice", uri.User)
 			assert.Equal(t, "atlanta.com", uri.Host)
 			assert.True(t, uri.IsEncrypted())
+			assert.Equal(t, "atlanta.com:5061", uri.HostPort())
 		}
 
 	})
diff --git a/sip/uri.go b/sip/uri.go
index 4c953bb..c0779aa 100644
--- a/sip/uri.go
+++ b/sip/uri.go
@@ -145,6 +145,16 @@ func (uri *Uri) Addr() string {
 
 // HostPort represents host:port part
 func (uri *Uri) HostPort() string {
-	p := strconv.Itoa(uri.Port)
+	transport := TransportTCP
+	if uri.IsEncrypted() {
+		transport = TransportTLS
+	}
+
+	port := uri.Port
+	if port == 0 {
+		port = DefaultPort(transport)
+	}
+
+	p := strconv.Itoa(port)
 	return uri.Host + ":" + p
 }