diff --git a/include/xo/object2/DArray.hpp b/include/xo/object2/DArray.hpp
index 0dc13cd..097b9a4 100644
--- a/include/xo/object2/DArray.hpp
+++ b/include/xo/object2/DArray.hpp
@@ -23,7 +23,7 @@ namespace xo {
          *  fixed at construction time, but not part of type.
          *  Can reallocate to change
          **/
-        struct DArray {
+        class DArray {
         public:
             /** @defgroup darray-types type traits **/
             ///@{
diff --git a/include/xo/object2/number/GCObjectConversion_DFloat.hpp b/include/xo/object2/number/GCObjectConversion_DFloat.hpp
index 8ce4b2b..959eeca 100644
--- a/include/xo/object2/number/GCObjectConversion_DFloat.hpp
+++ b/include/xo/object2/number/GCObjectConversion_DFloat.hpp
@@ -19,7 +19,7 @@ namespace xo {
             using AGCObject = xo::mm::AGCObject;
             using AAllocator = xo::mm::AAllocator;
 
-            static obj<AGCObject> to_gco(obj<AAllocator> mm, const double & x);
+            static obj<AGCObject> to_gco(obj<AAllocator> mm, double x);
             static double from_gco(obj<AAllocator> mm, obj<AGCObject> gco);
         };
 
diff --git a/include/xo/object2/number/GCObjectConversion_DInteger.hpp b/include/xo/object2/number/GCObjectConversion_DInteger.hpp
new file mode 100644
index 0000000..458312c
--- /dev/null
+++ b/include/xo/object2/number/GCObjectConversion_DInteger.hpp
@@ -0,0 +1,29 @@
+/** @file GCObjectConversion_DInteger.hpp
+ *
+ *  @author Roland Conybeare, Jan 2026
+ **/
+
+#pragma once
+
+#include "DInteger.hpp"
+#include "number/IGCObject_DInteger.hpp"
+#include <xo/gc/GCObjectConversion.hpp>
+
+namespace xo {
+    namespace scm {
+
+        template <>
+        struct GCObjectConversion<long> {
+            static_assert(std::is_same_v<long, DInteger::value_type>);
+
+            using AGCObject = xo::mm::AGCObject;
+            using AAllocator = xo::mm::AAllocator;
+
+            static obj<AGCObject> to_gco(obj<AAllocator> mm, long x);
+            static long from_gco(obj<AAllocator> mm, obj<AGCObject> gco);
+        };
+
+    }
+} /*namespace xo*/
+
+/* end GCObjectConversion_DInteger.hpp */
diff --git a/src/object2/CMakeLists.txt b/src/object2/CMakeLists.txt
index 2902a4e..2ea8a07 100644
--- a/src/object2/CMakeLists.txt
+++ b/src/object2/CMakeLists.txt
@@ -6,6 +6,7 @@ set(SELF_SRCS
     object2_register_types.cpp
     object2_register_facets.cpp
     GCObjectConversion_DFloat.cpp
+    GCObjectConversion_DInteger.cpp
     IGCObject_DArray.cpp
     IGCObject_DFloat.cpp
     IGCObject_DBoolean.cpp
diff --git a/src/object2/GCObjectConversion_DFloat.cpp b/src/object2/GCObjectConversion_DFloat.cpp
index a99c68c..794431d 100644
--- a/src/object2/GCObjectConversion_DFloat.cpp
+++ b/src/object2/GCObjectConversion_DFloat.cpp
@@ -13,7 +13,7 @@ namespace xo {
 
         obj<AGCObject>
         GCObjectConversion<double>::to_gco(obj<AAllocator> mm,
-                                           const double & x)
+                                           double x)
         {
             return DFloat::box<AGCObject>(mm, x);
         }
diff --git a/src/object2/GCObjectConversion_DInteger.cpp b/src/object2/GCObjectConversion_DInteger.cpp
new file mode 100644
index 0000000..bdaf8a1
--- /dev/null
+++ b/src/object2/GCObjectConversion_DInteger.cpp
@@ -0,0 +1,41 @@
+/** @file GCObjectConversion_DInteger.cpp
+ *
+ *  @author Roland Conybeare, Jan 2026
+ **/
+
+#include "number/GCObjectConversion_DInteger.hpp"
+#include <xo/indentlog/print/tag.hpp>
+
+namespace xo {
+    using xo::mm::AGCObject;
+
+    namespace scm {
+
+        obj<AGCObject>
+        GCObjectConversion<long>::to_gco(obj<AAllocator> mm,
+                                           long x)
+        {
+            return DInteger::box<AGCObject>(mm, x);
+        }
+
+        long
+        GCObjectConversion<long>::from_gco(obj<AAllocator> mm,
+                                           obj<AGCObject> gco)
+        {
+            (void)mm;
+
+            auto int_obj = obj<AGCObject,DInteger>::from(gco);
+
+            if (!int_obj) {
+                throw std::runtime_error
+                    (tostr("Object obj found where Integer expected",
+                           xtag("obj", gco)));
+            }
+
+            return int_obj.data()->value();
+        }
+
+    } /*namespace scm*/
+} /*namespace xo*/
+
+/* end GCObjectConversion_DFloat.cpp */