diff --git a/include/xo/interpreter2/DLocalEnv.hpp b/include/xo/interpreter2/DLocalEnv.hpp
index 4cbe3f7d..a9253bbc 100644
--- a/include/xo/interpreter2/DLocalEnv.hpp
+++ b/include/xo/interpreter2/DLocalEnv.hpp
@@ -16,6 +16,7 @@ namespace xo {
         class DLocalEnv {
         public:
             using DArray = xo::scm::DArray;
+            using ACollector = xo::mm::ACollector;
             using AGCObject = xo::mm::AGCObject;
             using AGCObjectVisitor = xo::mm::AGCObjectVisitor;
             using VisitReason = xo::mm::VisitReason;
@@ -49,7 +50,7 @@ namespace xo {
             obj<AGCObject> lookup_value(Binding ix) const noexcept;
 
             /** assign value associated with binding @p ix to @p x **/
-            void assign_value(Binding ix, obj<AGCObject> x);
+            void assign_value(obj<AAllocator> mm, Binding ix, obj<AGCObject> x);
 
             ///@}
             /** @defgroup scm-localenv-gcobject-facet **/
diff --git a/include/xo/interpreter2/sequence/IGCObject_DVsmSeqContFrame.hpp b/include/xo/interpreter2/sequence/IGCObject_DVsmSeqContFrame.hpp
index 907e3fb2..f45f9d0b 100644
--- a/include/xo/interpreter2/sequence/IGCObject_DVsmSeqContFrame.hpp
+++ b/include/xo/interpreter2/sequence/IGCObject_DVsmSeqContFrame.hpp
@@ -67,4 +67,4 @@ when @p fn invokes garbage collector reentry point **/
     } /*namespace scm*/
 } /*namespace xo*/
 
-/* end */
\ No newline at end of file
+/* end */
diff --git a/src/interpreter2/DLocalEnv.cpp b/src/interpreter2/DLocalEnv.cpp
index 0e805d1b..6877f971 100644
--- a/src/interpreter2/DLocalEnv.cpp
+++ b/src/interpreter2/DLocalEnv.cpp
@@ -63,7 +63,9 @@ namespace xo {
         }
 
         void
-        DLocalEnv::assign_value(Binding ix, obj<AGCObject> x)
+        DLocalEnv::assign_value(obj<AAllocator> mm,
+                                Binding ix,
+                                obj<AGCObject> x)
         {
             scope log(XO_DEBUG(true));
 
@@ -79,8 +81,7 @@ namespace xo {
                 auto j = ix.j_slot();
 
                 if (j < static_cast<decltype(j)>(env->n_vars())) {
-                    log && log("STUB: need write barrier for GC here");
-                    (*(env->args_))[j] = x;
+                    env->args_->assign_at(mm, j, x);
                 } else {
                     assert(false);
                 }
diff --git a/src/interpreter2/DVirtualSchematikaMachine.cpp b/src/interpreter2/DVirtualSchematikaMachine.cpp
index fc64e2e8..c8604e50 100644
--- a/src/interpreter2/DVirtualSchematikaMachine.cpp
+++ b/src/interpreter2/DVirtualSchematikaMachine.cpp
@@ -821,9 +821,9 @@ namespace xo {
 
                 log && log(xtag("i_arg", i_arg), xtag("n_arg", args->size()), xtag("cap", args->capacity()));
 
-                auto gc = mm_.to_op().to_facet<ACollector>();
+                //auto gc = mm_.to_op().to_facet<ACollector>();
 
-                args->push_back(gc, value);
+                args->push_back(mm_.to_op(), value);
 
                 i_arg = evalargs_frame->increment_arg();