diff --git a/link/mame.fnl b/link/mame.fnl
index 5660d7e..6b47c55 100644
--- a/link/mame.fnl
+++ b/link/mame.fnl
@@ -70,7 +70,7 @@
          (var last-addr ?last-addr)
          (while (let [state manager.machine.debugger.execution_state
                       addr (. manager.machine.devices ::maincpu :state :PC :value)]
-                    (not (and (= state :stop) (not= addr ?last-addr))))
+                    (not (and (= state :stop) (not= addr last-addr))))
            (when (= :run manager.machine.debugger.execution_state)
              (set last-addr nil))
            (coroutine.yield))))