diff --git a/src/lib.rs b/src/lib.rs
index 9ad1689..8a7d3b4 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -274,7 +274,7 @@ impl<T: Ord> BinarySearchTree<T> {
     }
 
     pub fn is_empty(&self) -> bool {
-        self.root.is_none()
+        self.size == 0
     }
 
     pub fn insert(&mut self, value: T) {