diff --git a/src/server/router/router.go b/src/server/router/router.go
index c29d8ec..c225b11 100644
--- a/src/server/router/router.go
+++ b/src/server/router/router.go
@@ -50,9 +50,15 @@ func (r *Router) resolve(path string) *Route {
 
 func (r *Router) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
 	// autoclose open base url
-	if r.base != "" && r.base == req.URL.Path {
-		http.Redirect(rw, req, r.base+"/", http.StatusFound)
-		return
+	if r.base != "" {
+		if r.base == req.URL.Path {
+			http.Redirect(rw, req, r.base+"/", http.StatusFound)
+			return
+		}
+		if !strings.HasPrefix(req.URL.Path, r.base) {
+			rw.WriteHeader(http.StatusNotFound)
+			return
+		}
 	}
 
 	path := strings.TrimPrefix(req.URL.Path, r.base)
diff --git a/src/server/router/router_test.go b/src/server/router/router_test.go
index dba5873..4230fcb 100644
--- a/src/server/router/router_test.go
+++ b/src/server/router/router_test.go
@@ -118,7 +118,6 @@ func TestRouterBase(t *testing.T) {
 
 	recorder := httptest.NewRecorder()
 	request := httptest.NewRequest("GET", "/foo/bar", nil)
-
 	router.ServeHTTP(recorder, request)
 
 	if recorder.Result().StatusCode != 200 {
@@ -130,6 +129,20 @@ func TestRouterBase(t *testing.T) {
 	}
 }
 
+func TestRouterBase404(t *testing.T) {
+	router := NewRouter("/foo")
+	router.For("/bar", func(c *Context) {
+		c.Out.Write([]byte("!!!"))
+	})
+
+	recorder := httptest.NewRecorder()
+	request := httptest.NewRequest("GET", "/bar", nil)
+	router.ServeHTTP(recorder, request)
+	if recorder.Result().StatusCode != 404 {
+		t.Fatal("expected 404")
+	}
+}
+
 func TestRouterBaseRedirect(t *testing.T) {
 	router := NewRouter("/foo")
 	router.For("/", func(c *Context) {