diff --git a/kitty/dnd.c b/kitty/dnd.c
index 53d844af1..1ab902125 100644
--- a/kitty/dnd.c
+++ b/kitty/dnd.c
@@ -49,6 +49,7 @@ machine_id(void) {
 
 void
 dnd_set_test_write_func(PyObject *func) {
+    (void)machine_id;
     Py_XDECREF(g_dnd_test_write_func);
     g_dnd_test_write_func = Py_XNewRef(func);
 }