diff --git a/pkgs/maprouter/maprouter_test.go b/pkgs/maprouter/maprouter_test.go
new file mode 100644
index 0000000..c27938c
--- /dev/null
+++ b/pkgs/maprouter/maprouter_test.go
@@ -0,0 +1,54 @@
+package maprouter
+
+import (
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestMapRouter(t *testing.T) {
+	router := &MapRouter{
+		DefaultHandler: http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {
+			rw.Write([]byte("Default"))
+		}),
+		Handlers: map[string]http.Handler{
+			"a.example.org": http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {
+				rw.Write([]byte("a"))
+			}),
+			"b.example.org": http.HandlerFunc(func(rw http.ResponseWriter, r *http.Request) {
+				rw.Write([]byte("b"))
+			}),
+		},
+	}
+
+	req := httptest.NewRequest(http.MethodGet, "http://a.example.org", nil)
+	rec := httptest.NewRecorder()
+	router.ServeHTTP(rec, req)
+	resBody, _ := io.ReadAll(rec.Result().Body)
+	assert.Equal(t, "a", string(resBody))
+
+	req = httptest.NewRequest(http.MethodGet, "http://b.example.org", nil)
+	rec = httptest.NewRecorder()
+	router.ServeHTTP(rec, req)
+	resBody, _ = io.ReadAll(rec.Result().Body)
+	assert.Equal(t, "b", string(resBody))
+
+	req = httptest.NewRequest(http.MethodGet, "http://c.example.org", nil)
+	rec = httptest.NewRecorder()
+	router.ServeHTTP(rec, req)
+	resBody, _ = io.ReadAll(rec.Result().Body)
+	assert.Equal(t, "Default", string(resBody))
+
+	router.KeyFunc = func(r *http.Request) string {
+		return "a.example.org"
+	}
+
+	req = httptest.NewRequest(http.MethodGet, "http://c.example.org", nil)
+	rec = httptest.NewRecorder()
+	router.ServeHTTP(rec, req)
+	resBody, _ = io.ReadAll(rec.Result().Body)
+	assert.Equal(t, "a", string(resBody))
+}