diff --git a/src/vm/mod.rs b/src/vm/mod.rs
index ca25005..60f6e78 100644
--- a/src/vm/mod.rs
+++ b/src/vm/mod.rs
@@ -55,14 +55,12 @@ pub fn run(mut prog: Program) -> Result<p::Value> {
     let arena: Arena<Rootable![GcRoot<'_>]> = Arena::new(|mc| {
         new(&mut prog, mc)
     });
-    eval(prog.top_level.into_iter(), &arena, |val| {
-        Ok(arena.mutate(|_, root: &GcRoot| {
-            val.to_public(&root.vm, &mut HashSet::new())
-        }))
+    eval(prog.top_level.into_iter(), &arena, |val, vm| {
+        Ok(val.to_public(vm, &mut HashSet::new()))
     })
 }
 
-fn eval<'gc, T, F: for<'a> FnOnce(Value<'a>) -> Result<T>>(
+fn eval<'gc, T, F: for<'a> FnOnce(Value<'a>, &VM<'a>) -> Result<T>>(
     opcodes: impl Iterator<Item = OpCode>,
     arena: &Arena<impl for<'a> Rootable<'a, Root = GcRoot<'a>>>,
     f: F
@@ -87,7 +85,7 @@ fn eval<'gc, T, F: for<'a> FnOnce(Value<'a>) -> Result<T>>(
         assert_eq!(ctx.stack.len(), 1);
         let mut ret = ctx.stack.pop();
         ret.force(&root.vm, mc);
-        f(ret)
+        f(ret, &root.vm)
     })
 }