diff --git a/include/xo/gc/detail/IGCObjectVisitor_DX1Collector.hpp b/include/xo/gc/detail/IGCObjectVisitor_DX1Collector.hpp
index c2696a7..6512f88 100644
--- a/include/xo/gc/detail/IGCObjectVisitor_DX1Collector.hpp
+++ b/include/xo/gc/detail/IGCObjectVisitor_DX1Collector.hpp
@@ -47,6 +47,10 @@ namespace xo {
             // const methods
 
             // non-const methods
+            /** allocate copy of source object at address @p src.
+Source must be owned by this collector.
+Increments object age **/
+            static void * alloc_copy(DX1Collector & self, std::byte * src);
             /** visit child of a gc-aware object. May update child in-place! **/
             static void visit_child(DX1Collector & self, AGCObject * iface, void ** pp_data) noexcept;
             ///@}
diff --git a/src/gc/GCObjectStore.cpp b/src/gc/GCObjectStore.cpp
index ee900b5..33d2d24 100644
--- a/src/gc/GCObjectStore.cpp
+++ b/src/gc/GCObjectStore.cpp
@@ -454,7 +454,7 @@ namespace xo {
         }
 
         void
-        GCObjectStore::forward_inplace_aux(DX1Collector * gc,
+        GCObjectStore::forward_inplace_aux(DX1Collector * x1gc,
                                            AGCObject * lhs_iface,
                                            void ** lhs_data,
                                            Generation upto)
@@ -498,7 +498,7 @@ namespace xo {
                 log && log("disposition: not in from-space. Don't forward, but check children");
 
                 obj<AGCObject> gco(lhs_iface, object_data);
-                gco.visit_gco_children(gc->ref<AGCObjectVisitor>());
+                gco.visit_gco_children(x1gc->ref<AGCObjectVisitor>());
 
                 return;
             }
@@ -609,7 +609,7 @@ namespace xo {
                  *                                    +----------+
                  */
 
-                *lhs_data = this->_shallow_move(gc, lhs_iface, *lhs_data);
+                *lhs_data = this->_shallow_move(x1gc, lhs_iface, *lhs_data);
 
                 /*
                  *   lhs   obj<AGCObject>             (from-space)
@@ -860,7 +860,7 @@ namespace xo {
         } /*_deep_move_gc_owned*/
 
         void *
-        GCObjectStore::_shallow_move(DX1Collector * gc,
+        GCObjectStore::_shallow_move(DX1Collector * x1gc,
                                      AGCObject * iface,
                                      void * from_src)
         {
@@ -870,7 +870,7 @@ namespace xo {
 
             //obj<AAllocator, DX1Collector> gc_gco(gc);
 
-            void * to_dest = iface->shallow_move(from_src, gc->ref<ACollector>());
+            void * to_dest = iface->shallow_move(from_src, x1gc->ref<ACollector>());
 
             log && log(xtag("from_src", from_src), xtag("to_dest", to_dest));
             log && log(xtag("tseq", info.tseq()),
diff --git a/src/gc/facet/IGCObjectVisitor_DX1Collector.cpp b/src/gc/facet/IGCObjectVisitor_DX1Collector.cpp
index edb3506..d4c609c 100644
--- a/src/gc/facet/IGCObjectVisitor_DX1Collector.cpp
+++ b/src/gc/facet/IGCObjectVisitor_DX1Collector.cpp
@@ -15,6 +15,11 @@
 
 namespace xo {
     namespace mm {
+        auto
+        IGCObjectVisitor_DX1Collector::alloc_copy(DX1Collector & self, std::byte * src) -> void *
+        {
+            return self.alloc_copy(src);
+        }
         auto
         IGCObjectVisitor_DX1Collector::visit_child(DX1Collector & self, AGCObject * iface, void ** pp_data) noexcept -> void
         {