diff --git a/ip/resolver/basic_http/service.go b/ip/resolver/basic_http/service.go
index a3a3d07..fb5963b 100644
--- a/ip/resolver/basic_http/service.go
+++ b/ip/resolver/basic_http/service.go
@@ -7,6 +7,8 @@ import (
 	"net"
 	"net/http"
 	"strings"
+
+	"dnsupdater/ip"
 )
 
 type Service struct {
@@ -44,9 +46,5 @@ func (s Service) Lookup(ctx context.Context) (net.IP, error) {
 	// Trim spaces and stuff.
 	ip_str := strings.TrimSpace(string(body))
 
-	ip := net.ParseIP(ip_str)
-	if ip == nil {
-		err = fmt.Errorf("Failed to parse ip: %s", ip_str)
-	}
-	return ip, err
+	return ip.ParseIP(ip_str)
 }
diff --git a/ip/resolver/basic_http/service_test.go b/ip/resolver/basic_http/service_test.go
index d191f5d..6495462 100644
--- a/ip/resolver/basic_http/service_test.go
+++ b/ip/resolver/basic_http/service_test.go
@@ -80,6 +80,6 @@ func TestService_Lookup_ParseError(t *testing.T) {
 	}
 
 	ip, err := s.Lookup(context.Background())
-	assert.EqualError(t, err, "Failed to parse ip: random_string")
+	assert.EqualError(t, err, "invalid IP address: random_string")
 	assert.Nil(t, ip)
 }
diff --git a/ip/resolver/jsonip/service.go b/ip/resolver/jsonip/service.go
index 6af1e16..04e7136 100644
--- a/ip/resolver/jsonip/service.go
+++ b/ip/resolver/jsonip/service.go
@@ -5,6 +5,8 @@ import (
 	"encoding/json"
 	"net"
 	"net/http"
+
+	"dnsupdater/ip"
 )
 
 type Service struct {
@@ -22,12 +24,7 @@ func (s Service) Name() string {
 }
 
 func (s Service) Lookup(ctx context.Context) (net.IP, error) {
-	req, err := http.NewRequestWithContext(ctx, "GET", s.url, nil)
-	if err != nil {
-		return nil, err
-	}
-
-	resp, err := http.DefaultClient.Do(req)
+	resp, err := httphelper.Get(ctx, s.url, nil)
 	if err != nil {
 		return nil, err
 	}
@@ -41,5 +38,5 @@ func (s Service) Lookup(ctx context.Context) (net.IP, error) {
 		return nil, err
 	}
 
-	return net.ParseIP(v.Ip), err
+	return ip.ParseIP(v.Ip)
 }