diff --git a/cmd/protoc-gen-go-http/http.go b/cmd/protoc-gen-go-http/http.go
index 0d9458d82..5a363af31 100644
--- a/cmd/protoc-gen-go-http/http.go
+++ b/cmd/protoc-gen-go-http/http.go
@@ -236,8 +236,8 @@ func replacePath(name string, value string, path string) string {
 }
 
 func camelCaseVars(s string) string {
-	vars := make([]string, 0)
 	subs := strings.Split(s, ".")
+	vars := make([]string, 0, len(subs))
 	for _, sub := range subs {
 		vars = append(vars, camelCase(sub))
 	}
diff --git a/contrib/config/etcd/config.go b/contrib/config/etcd/config.go
index ea027c2a9..854b0a961 100644
--- a/contrib/config/etcd/config.go
+++ b/contrib/config/etcd/config.go
@@ -77,7 +77,7 @@ func (s *source) Load() ([]*config.KeyValue, error) {
 	if err != nil {
 		return nil, err
 	}
-	kvs := make([]*config.KeyValue, 0)
+	kvs := make([]*config.KeyValue, 0, len(rsp.Kvs))
 	for _, item := range rsp.Kvs {
 		k := string(item.Key)
 		kvs = append(kvs, &config.KeyValue{
diff --git a/examples/blog/internal/data/article.go b/examples/blog/internal/data/article.go
index c13cdf879..14fc67526 100644
--- a/examples/blog/internal/data/article.go
+++ b/examples/blog/internal/data/article.go
@@ -26,7 +26,7 @@ func (ar *articleRepo) ListArticle(ctx context.Context) ([]*biz.Article, error)
 	if err != nil {
 		return nil, err
 	}
-	rv := make([]*biz.Article, 0)
+	rv := make([]*biz.Article, 0, len(ps))
 	for _, p := range ps {
 		rv = append(rv, &biz.Article{
 			ID:        p.ID,