diff --git a/artiq/compiler/transforms/artiq_ir_generator.py b/artiq/compiler/transforms/artiq_ir_generator.py
index 068d75cdd..2a7f56d26 100644
--- a/artiq/compiler/transforms/artiq_ir_generator.py
+++ b/artiq/compiler/transforms/artiq_ir_generator.py
@@ -878,8 +878,8 @@ class ARTIQIRGenerator(algorithm.Visitor):
                     self.current_assign = None
 
                 none = self.append(ir.Alloc([], builtins.TNone()))
-                call = self._user_call(exit_fn, [none, none, none], {})
-                cleanup.append(lambda: call)
+                cleanup.append(lambda:
+                    self._user_call(exit_fn, [none, none, none], {}))
 
         self._try_finally(
             body_gen=lambda: self.visit(node.body),