diff --git a/valuescript_vm/src/unary_op.rs b/valuescript_vm/src/unary_op.rs
index 6e4ba4d..4fdda42 100644
--- a/valuescript_vm/src/unary_op.rs
+++ b/valuescript_vm/src/unary_op.rs
@@ -1,4 +1,4 @@
-#[derive(Clone, Debug, PartialEq, Eq)]
+#[derive(Copy, Clone, Debug, PartialEq, Eq)]
 pub enum UnaryOp {
   Plus,
   Minus,