diff --git a/src/type/DArrayType.cpp b/src/type/DArrayType.cpp
index 52d25f5..46bad06 100644
--- a/src/type/DArrayType.cpp
+++ b/src/type/DArrayType.cpp
@@ -85,7 +85,7 @@ namespace xo {
         DArrayType *
         DArrayType::shallow_move(obj<ACollector> gc) noexcept
         {
-            return gc.std_copy_for(this);
+            return gc.std_move_for(this);
         }
 
         std::size_t
diff --git a/src/type/DAtomicType.cpp b/src/type/DAtomicType.cpp
index d4f0b16..c5d3033 100644
--- a/src/type/DAtomicType.cpp
+++ b/src/type/DAtomicType.cpp
@@ -63,7 +63,7 @@ namespace xo {
         DAtomicType *
         DAtomicType::shallow_move(obj<ACollector> gc) noexcept
         {
-            return gc.std_copy_for(this);
+            return gc.std_move_for(this);
         }
 
         std::size_t
diff --git a/src/type/DFunctionType.cpp b/src/type/DFunctionType.cpp
index 8cb9001..83462b8 100644
--- a/src/type/DFunctionType.cpp
+++ b/src/type/DFunctionType.cpp
@@ -96,7 +96,7 @@ namespace xo {
         DFunctionType *
         DFunctionType::shallow_move(obj<ACollector> gc) noexcept
         {
-            return gc.std_copy_for(this);
+            return gc.std_move_for(this);
         }
 
         std::size_t
diff --git a/src/type/DListType.cpp b/src/type/DListType.cpp
index 487cc5f..4955777 100644
--- a/src/type/DListType.cpp
+++ b/src/type/DListType.cpp
@@ -90,7 +90,7 @@ namespace xo {
         DListType *
         DListType::shallow_move(obj<ACollector> gc) noexcept
         {
-            return gc.std_copy_for(this);
+            return gc.std_move_for(this);
         }
 
         std::size_t
diff --git a/src/type/DTypeVarRef.cpp b/src/type/DTypeVarRef.cpp
index a712174..e9119d1 100644
--- a/src/type/DTypeVarRef.cpp
+++ b/src/type/DTypeVarRef.cpp
@@ -84,7 +84,7 @@ namespace xo {
         DTypeVarRef *
         DTypeVarRef::shallow_move(obj<ACollector> gc) noexcept
         {
-            return gc.std_copy_for(this);
+            return gc.std_move_for(this);
         }
 
         std::size_t