diff --git a/src/helpers/path_ext.rs b/src/helpers/path_ext.rs
index c1261f96..c4958539 100644
--- a/src/helpers/path_ext.rs
+++ b/src/helpers/path_ext.rs
@@ -1,6 +1,8 @@
 use std::path::{Component, Path, PathBuf};
 
 pub trait PathExt {
+    /// Similiar to `os.path.normpath`: It does not perform
+    /// any fs operation.
     fn normalize_path(&self) -> PathBuf;
 }