diff --git a/etc/xo/subsystem-list b/etc/xo/subsystem-list
index 0086b814..409b7ea4 100644
--- a/etc/xo/subsystem-list
+++ b/etc/xo/subsystem-list
@@ -6,6 +6,7 @@ xo-flatstring
 xo-reflectutil
 xo-arena
 xo-facet
+xo-printable2
 xo-testutil
 xo-alloc2
 xo-gc