diff --git a/example/server/main.go b/example/server/main.go
index 7d7f29b..ddbe403 100644
--- a/example/server/main.go
+++ b/example/server/main.go
@@ -19,8 +19,9 @@ import (
 )
 
 type conf struct {
-	Name string `json:"name" default:"john"`
-	Age  int    `json:"age"`
+	Name    string   `json:"name" default:"john"`
+	Age     int      `json:"age"`
+	Friends []string `json:"friends" default:"[\"mark\",\"tom\",\"jack\"]"`
 }
 
 func (c *conf) Update(new config.Config) error {
@@ -30,6 +31,7 @@ func (c *conf) Update(new config.Config) error {
 	}
 	c.Name = newCfg.Name
 	c.Age = newCfg.Age
+	c.Friends = newCfg.Friends
 	return nil
 }
 
diff --git a/example/server/server.go b/example/server/server.go
index c319512..3ef8b9b 100644
--- a/example/server/server.go
+++ b/example/server/server.go
@@ -90,14 +90,14 @@ func (s *server) listConfigsHandler(w http.ResponseWriter, r *http.Request) {
 	if err != nil {
 		w.WriteHeader(http.StatusBadRequest)
 		fmt.Fprintf(w, "fromVersion must be a non-negative integer")
-		s.lgr.With("error", err).ErrorContext(r.Context(), "parsing from-version string %s", fromVersionStr)
+		s.lgr.With("error", err).ErrorContext(r.Context(), fmt.Sprintf("parsing from-version string %s", fromVersionStr))
 		return
 	}
 	toVersion, err := strconv.ParseUint(toVersionStr, 0, 32)
 	if err != nil {
-		s.lgr.With("error", err).ErrorContext(r.Context(), "parsing to-version string %s", toVersionStr)
-		fmt.Fprintf(w, "toVersion must be a non-negative integer")
 		w.WriteHeader(http.StatusBadRequest)
+		fmt.Fprintf(w, "toVersion must be a non-negative integer")
+		s.lgr.With("error", err).ErrorContext(r.Context(), fmt.Sprintf("parsing to-version string %s", toVersionStr))
 		return
 	}
 	versions, err := s.repo.ListVersionedConfigs(r.Context(), config.ListVersionedConfigsQuery{