diff --git a/src/command/build/render.rs b/src/command/build/render.rs
index 530fba1..ef0a1aa 100644
--- a/src/command/build/render.rs
+++ b/src/command/build/render.rs
@@ -263,9 +263,11 @@ fn build_name_contents_pairs<'a>(
     Ok((name, contents))
 }
 
+type ReadFileResult = std::io::Result<(PathBuf, Vec<u8>)>;
+
 fn get_all_files<P: AsRef<Path>>(
     root_dir: P,
-) -> Result<impl Iterator<Item = JoinHandle<std::io::Result<(PathBuf, Vec<u8>)>>>, walkdir::Error> {
+) -> Result<impl Iterator<Item = JoinHandle<ReadFileResult>>, walkdir::Error> {
     let files = WalkDir::new(root_dir)
         .into_iter()
         .filter(|e| match e {
@@ -280,7 +282,7 @@ fn get_all_files<P: AsRef<Path>>(
     Ok(org_files)
 }
 
-async fn read_file(path: PathBuf) -> std::io::Result<(PathBuf, Vec<u8>)> {
+async fn read_file(path: PathBuf) -> ReadFileResult {
     let contents = tokio::fs::read(&path).await?;
     Ok((path, contents))
 }