diff --git a/src/procedure2/SetupProcedure2.cpp b/src/procedure2/SetupProcedure2.cpp
index 520df9b..9dec25c 100644
--- a/src/procedure2/SetupProcedure2.cpp
+++ b/src/procedure2/SetupProcedure2.cpp
@@ -109,6 +109,10 @@ namespace xo {
                        (sink,
                         ObjectPrimitives::make_cons_pm(mm, stbl),
                         flags & InstallFlags::f_generalpurpose));
+            ok = ok & (PrimitiveRegistry::install_aux
+                       (sink,
+                        ObjectPrimitives::make_set_car_pm(mm, stbl),
+                        flags & InstallFlags::f_generalpurpose));
             ok = ok & (PrimitiveRegistry::install_aux
                        (sink,
                         ObjectPrimitives::make_dict_make_pm(mm, stbl),