diff --git a/grpcstub.go b/grpcstub.go
index bd772b5..dc584ed 100644
--- a/grpcstub.go
+++ b/grpcstub.go
@@ -518,6 +518,7 @@ func (s *Server) ClearMatchers() {
 	s.matchers = nil
 }
 
+// Prepend prepend matcher.
 func (s *Server) Prepend() *Server {
 	s.mu.Lock()
 	defer s.mu.Unlock()
diff --git a/grpcstub_test.go b/grpcstub_test.go
index eb6de77..dfbc337 100644
--- a/grpcstub_test.go
+++ b/grpcstub_test.go
@@ -814,6 +814,7 @@ func TestPrepend(t *testing.T) {
 		})
 		ts.Service("routeguide.RouteGuide").Response(map[string]any{"name": "hello"})
 		ts.Service("routeguide.RouteGuide").Response(map[string]any{"name": "world"})
+		ts.Service("routeguide.RouteGuide").Response(map[string]any{"name": "!!!"})
 
 		client := routeguide.NewRouteGuideClient(ts.Conn())
 		res, err := client.GetFeature(ctx, &routeguide.Point{
@@ -837,6 +838,7 @@ func TestPrepend(t *testing.T) {
 		})
 		ts.Service("routeguide.RouteGuide").Response(map[string]any{"name": "hello"})
 		ts.Prepend().Service("routeguide.RouteGuide").Response(map[string]any{"name": "world"})
+		ts.Service("routeguide.RouteGuide").Response(map[string]any{"name": "!!!"})
 
 		client := routeguide.NewRouteGuideClient(ts.Conn())
 		res, err := client.GetFeature(ctx, &routeguide.Point{