diff --git a/src/btree.rs b/src/btree.rs
index 2267f2f..2bff281 100644
--- a/src/btree.rs
+++ b/src/btree.rs
@@ -41,7 +41,7 @@ where
     ///
     /// let bimap = BiBTreeMap::<char, i32>::new();
     /// ```
-    pub fn new() -> Self {
+    pub const fn new() -> Self {
         Self {
             left2right: BTreeMap::new(),
             right2left: BTreeMap::new(),