diff --git a/ip/resolver/jsonip/service_test.go b/ip/resolver/jsonip/service_test.go
index ed7e419..c6ca9f8 100644
--- a/ip/resolver/jsonip/service_test.go
+++ b/ip/resolver/jsonip/service_test.go
@@ -43,3 +43,31 @@ func TestService_Lookup_HTTPError(t *testing.T) {
 	assert.EqualError(t, err, "HTTP Response: 404 Not Found")
 	assert.Nil(t, ip)
 }
+
+func TestService_Lookup_JsonParseError(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		_, err := w.Write([]byte(`invalid_json`))
+		assert.NoError(t, err)
+	}))
+	defer server.Close()
+
+	s := Service{url: server.URL}
+
+	ip, err := s.Lookup(context.Background())
+	assert.EqualError(t, err, "invalid character 'i' looking for beginning of value")
+	assert.Nil(t, ip)
+}
+
+func TestService_Lookup_IPParseError(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		_, err := w.Write([]byte(`{"ip":"xxx","geo-ip":"https://getjsonip.com/#plus","API Help":"https://getjsonip.com/#docs"}`))
+		assert.NoError(t, err)
+	}))
+	defer server.Close()
+
+	s := Service{url: server.URL}
+
+	ip, err := s.Lookup(context.Background())
+	assert.EqualError(t, err, "invalid IP address: xxx")
+	assert.Nil(t, ip)
+}