diff --git a/lit-test/test/iodelay/class.py b/lit-test/test/iodelay/class.py
index 32580c4c6..61ca122f8 100644
--- a/lit-test/test/iodelay/class.py
+++ b/lit-test/test/iodelay/class.py
@@ -1,7 +1,7 @@
 # RUN: %python -m artiq.compiler.testbench.signature %s >%t
 # RUN: OutputCheck %s --file-to-check=%t
 
-# CHECK-L: g: ()->NoneType delay(s->mu(1.0) mu)
+# CHECK-L: g: (i:<instance c {}>)->NoneType delay(s->mu(1.0) mu)
 def g(i):
     i.f(1.0)