diff --git a/lit-test/test/iodelay/order_invariance.py b/lit-test/test/iodelay/order_invariance.py
new file mode 100644
index 000000000..af5adf13c
--- /dev/null
+++ b/lit-test/test/iodelay/order_invariance.py
@@ -0,0 +1,10 @@
+# RUN: %python -m artiq.compiler.testbench.signature %s >%t
+# RUN: OutputCheck %s --file-to-check=%t
+
+# CHECK-L: g: ()->NoneType delay(s->mu(2.0) mu)
+def g():
+    f()
+    f()
+
+def f():
+    delay(1.0)