diff --git a/src/core/stack.rs b/src/core/stack.rs
index e3aab6f..6b596f1 100644
--- a/src/core/stack.rs
+++ b/src/core/stack.rs
@@ -243,6 +243,7 @@ macro_rules! define_stack_value {
             fmt_dump($dump_self:pat, $f:pat) = $fmt_dump_body:expr,
             $cast:ident($cast_self:pat): $cast_res:ty = $cast_body:expr,
             $into:ident$(,)?
+            $({ $($other:tt)* })?
         }
     ),*$(,)?}) => {
         #[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
@@ -303,6 +304,8 @@ macro_rules! define_stack_value {
             fn $into(self: Box<Self>) -> Result<Box<$ty>> {
                 Ok(self)
             }
+
+            $($($other)*)?
         })*
     };
 }
@@ -395,6 +398,11 @@ define_stack_value! {
             fmt_dump(v, f) = write!(f, "WordList{{{:?}}}", &v as *const _),
             as_word_list(v): WordList = Ok(v),
             into_word_list,
+            {
+                fn into_cont(self: Box<Self>) -> Result<Box<Cont>> {
+                    Ok(Box::new(self.finish()))
+                }
+            }
         },
         SharedBox(SharedBox) = {
             eq(a, b) = {
diff --git a/src/modules/control.rs b/src/modules/control.rs
index 54945b3..4ea6b59 100644
--- a/src/modules/control.rs
+++ b/src/modules/control.rs
@@ -230,17 +230,19 @@ impl Control {
     #[cmd(name = ":_", active, args(active = false, prefix = true))]
     #[cmd(name = "::_", active, args(active = true, prefix = true))]
     fn interpret_colon(ctx: &mut Context, active: bool, prefix: bool) -> Result<()> {
-        let cont = ctx.stack.pop_cont()?;
+        thread_local! {
+            static CREATE_AUX: Cont = Rc::new((|ctx| interpret_create_aux(ctx, None)) as cont::ContextWordFunc);
+        };
+
         let name = ctx.input.scan_word()?.ok_or(UnexpectedEof)?;
+        let mode = (active as u8) | (prefix as u8) << 1;
 
-        define_word(
-            &mut ctx.dictionary,
-            name.data.to_owned(),
-            *cont,
-            DefMode { active, prefix },
-        )?;
+        let cont = CREATE_AUX.with(|cont| cont.clone());
 
-        ctx.stack.push_argcount(0, ctx.dictionary.make_nop())
+        ctx.stack.push(name.data.to_owned())?;
+        ctx.stack.push_int(mode)?;
+        ctx.stack.push_int(2)?;
+        ctx.stack.push(cont)
     }
 
     #[cmd(name = "forget", args(word_from_stack = false))]