diff --git a/include/xo/gc/DX1Collector.hpp b/include/xo/gc/DX1Collector.hpp
index 78f1711..1f2ceba 100644
--- a/include/xo/gc/DX1Collector.hpp
+++ b/include/xo/gc/DX1Collector.hpp
@@ -110,7 +110,9 @@ namespace xo {
             // ----- access methods -----
 
             const X1CollectorConfig & config() const noexcept { return config_; }
+
             const GCObjectStore & gco_store() const noexcept { return gco_store_; }
+            GCObjectStore & gco_store() noexcept { return gco_store_; }
 
             std::string_view name() const noexcept { return config_.name_; }
             GCRunState runstate() const noexcept { return runstate_; }
@@ -289,11 +291,6 @@ namespace xo {
              **/
             bool check_move_policy(header_type alloc_hdr, void * object_data) const noexcept;
 
-            /** move interior subgraph at @p from_src to to-space.
-             *  no-op if not in gc-space.
-             **/
-            void * deep_move_interior(void * from_src, Generation upto);
-
             // ----- allocation -----
 
             /** simple allocation. allocate @p z bytes of memory
diff --git a/include/xo/gc/GCObjectStore.hpp b/include/xo/gc/GCObjectStore.hpp
index d07be56..67a5506 100644
--- a/include/xo/gc/GCObjectStore.hpp
+++ b/include/xo/gc/GCObjectStore.hpp
@@ -108,6 +108,13 @@ namespace xo {
              **/
             bool install_type(const AGCObject & meta) noexcept;
 
+            /** move interior subgraph at @p from_src to to-space.
+             *  no-op if not in gc-space.
+             **/
+            void * deep_move_interior(DX1Collector * gc,
+                                      void * from_src,
+                                      Generation upto);
+
             /** Common driver for _deep_move_root(), _deep_move_interior().
              *  Move object subgraph @p from_src on behalf of @p gc collection cycle,
              *  covering generations in [0 ,.., upto).
diff --git a/src/gc/DX1Collector.cpp b/src/gc/DX1Collector.cpp
index 1b4fbfc..56f5a74 100644
--- a/src/gc/DX1Collector.cpp
+++ b/src/gc/DX1Collector.cpp
@@ -845,6 +845,7 @@ namespace xo {
             }
         }
 
+#ifdef OBSOLETE
         void *
         DX1Collector::deep_move_interior(void * from_src,
                                          Generation upto)
@@ -861,6 +862,7 @@ namespace xo {
 
             return _deep_move_gc_owned(from_src, upto);
         }
+#endif
 
         /*
          * rules:
diff --git a/src/gc/GCObjectStore.cpp b/src/gc/GCObjectStore.cpp
index 874b518..6b09678 100644
--- a/src/gc/GCObjectStore.cpp
+++ b/src/gc/GCObjectStore.cpp
@@ -625,6 +625,24 @@ namespace xo {
             return true;
         }
 
+        void *
+        GCObjectStore::deep_move_interior(DX1Collector * gc,
+                                          void * from_src,
+                                          Generation upto)
+        {
+            scope log(XO_DEBUG(config_.debug_flag_));
+
+            if (!from_src)
+                return nullptr;
+
+            bool src_in_from_space = this->contains(role::from_space(), from_src);
+
+            if (!src_in_from_space)
+                return from_src;
+
+            return this->_deep_move_gc_owned(gc, from_src, upto);
+        }
+
         void *
         GCObjectStore::_deep_move_gc_owned(DX1Collector * gc,
                                            void * from_src,
diff --git a/src/gc/MutationLogStore.cpp b/src/gc/MutationLogStore.cpp
index 563d4bd..0495035 100644
--- a/src/gc/MutationLogStore.cpp
+++ b/src/gc/MutationLogStore.cpp
@@ -400,7 +400,7 @@ namespace xo {
 
                 ++counters.n_rescue_;
 
-                child_to = gc->deep_move_interior(child_fr, upto);
+                child_to = gc->gco_store().deep_move_interior(gc, child_fr, upto);
 
                 // update child pointer in parent object
                 *from_entry.p_data() = child_to;