diff --git a/src/bird/mem.rs b/src/bird/mem.rs
index 144c843..0a33ae6 100644
--- a/src/bird/mem.rs
+++ b/src/bird/mem.rs
@@ -1,12 +1,13 @@
 use std::collections::HashMap;
 use std::rc::Rc;
 
-#[derive(Debug, PartialEq, Clone, Hash)]
+#[derive(Debug, PartialEq, Clone)]
 enum Value {
     Null,
     Bool(bool),
     Number(f64),
-    String(String),
-    Object(HashMap<String, Value>),
-    Array(Vec<Value>),
+    String(Rc<String>),
+    Object(Rc<HashMap<String, Value>>),
+    Array(Rc<Vec<Value>>),
+    Fn(Rc<()>),
 }