diff --git a/include/xo/gc/detail/ICollector_DX1Collector.hpp b/include/xo/gc/detail/ICollector_DX1Collector.hpp
index 1ae5fac..6f203e7 100644
--- a/include/xo/gc/detail/ICollector_DX1Collector.hpp
+++ b/include/xo/gc/detail/ICollector_DX1Collector.hpp
@@ -107,6 +107,10 @@ Return false if installation fails (e.g. memory exhausted) **/
 
 Require: gc not in progress **/
             static void assign_member(DX1Collector & self, void * parent, obj<AGCObject> * p_lhs, obj<AGCObject> & rhs);
+            /** 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);
             /** evacuate @p *lhs, that refers to state with interface @p lhs_iface,
 to collector @p d's to-space. Replace *lhs_data with forwarding pointer
 
diff --git a/src/gc/facet/ICollector_DX1Collector.cpp b/src/gc/facet/ICollector_DX1Collector.cpp
index 33a28aa..261deaa 100644
--- a/src/gc/facet/ICollector_DX1Collector.cpp
+++ b/src/gc/facet/ICollector_DX1Collector.cpp
@@ -95,6 +95,11 @@ namespace xo {
             self.assign_member(parent, p_lhs, rhs);
         }
         auto
+        ICollector_DX1Collector::alloc_copy(DX1Collector & self, std::byte * src) -> void *
+        {
+            return self.alloc_copy(src);
+        }
+        auto
         ICollector_DX1Collector::forward_inplace(DX1Collector & self, AGCObject * lhs_iface, void ** lhs_data) -> void
         {
             self.forward_inplace(lhs_iface, lhs_data);