diff --git a/artiq/compiler/transforms/artiq_ir_generator.py b/artiq/compiler/transforms/artiq_ir_generator.py
index 14a45a0e4..068d75cdd 100644
--- a/artiq/compiler/transforms/artiq_ir_generator.py
+++ b/artiq/compiler/transforms/artiq_ir_generator.py
@@ -878,7 +878,8 @@ class ARTIQIRGenerator(algorithm.Visitor):
                     self.current_assign = None
 
                 none = self.append(ir.Alloc([], builtins.TNone()))
-                cleanup.append(lambda fn=exit_fn: self._user_call(fn, [none, none, none], {}))
+                call = self._user_call(exit_fn, [none, none, none], {})
+                cleanup.append(lambda: call)
 
         self._try_finally(
             body_gen=lambda: self.visit(node.body),