1 files changed, 13 insertions, 11 deletions

diff --git a/src/cmd/folders.rs b/src/cmd/folders.rs
index 7bf93f1..0133528 100644
--- a/src/cmd/folders.rs
+++ b/src/cmd/folders.rs
@@ -1,23 +1,25 @@
 use std::collections::BTreeSet;
 use std::ffi::{OsStr, OsString};
 use std::path::Path;
+use std::sync::OnceLock;
 
-use lazy_static::lazy_static;
 use maildir::Maildir;
 
 use crate::error::Result;
 
-lazy_static! {
-    static ref REQUIRED_MAILDIR_DIRS: BTreeSet<OsString> = [
-        OsString::from("cur"),
-        "new".into(),
-        "tmp".into(),
-        "maildirfolder".into(),
-    ]
-    .into();
-}
+static REQUIRED_MAILDIR_DIRS: OnceLock<BTreeSet<OsString>> = OnceLock::new();
 
 fn is_mailsubdir(p: &Path) -> bool {
+    let rmd = REQUIRED_MAILDIR_DIRS.get_or_init(|| {
+        [
+            OsString::from("cur"),
+            "new".into(),
+            "tmp".into(),
+            "maildirfolder".into(),
+        ]
+        .into()
+    });
+
     p.is_dir()
         && p.file_name()
             .map_or(false, |fname| fname.to_string_lossy().starts_with('.'))
@@ -29,7 +31,7 @@ fn is_mailsubdir(p: &Path) -> bool {
                         .and_then(|dir_entry| dir_entry.path().file_name().map(OsStr::to_owned))
                 })
                 .collect::<BTreeSet<_>>()
-                .is_superset(&REQUIRED_MAILDIR_DIRS)
+                .is_superset(rmd)
             })
             .unwrap_or_default()
 }