diff --git a/include/xo/reflect/SelfTagging.hpp b/include/xo/reflect/SelfTagging.hpp
index b41d4ce..12eb279 100644
--- a/include/xo/reflect/SelfTagging.hpp
+++ b/include/xo/reflect/SelfTagging.hpp
@@ -10,22 +10,22 @@
 #include "TaggedRcptr.hpp"
 
 namespace xo {
-  namespace reflect {
-    /* a self-tagging object uses reflection to preserve type information
-     * until runtime.   Can use the reflected information to traverse
-     * object representation (e.g. for printing / serialization)
-     * without repetitive/bulky boilerplate.
-     *
-     * For pybind11 need to have concrete (non-template) apis,
-     * helpful to have various classes inherit SelfTagging
-     *
-     * For example see [printjson/PrintJson.hpp]
-     */
-    class SelfTagging : public ref::Refcount {
-    public:
-      virtual TaggedRcptr self_tp() = 0;
-    }; /*SelfTagging*/
-  } /*namespace reflect*/
+    namespace reflect {
+        /* a self-tagging object uses reflection to preserve type information
+         * until runtime.   Can use the reflected information to traverse
+         * object representation (e.g. for printing / serialization)
+         * without repetitive/bulky boilerplate.
+         *
+         * For pybind11 need to have concrete (non-template) apis,
+         * helpful to have various classes inherit SelfTagging
+         *
+         * For example see [printjson/PrintJson.hpp]
+         */
+        class SelfTagging : public ref::Refcount {
+        public:
+            virtual TaggedRcptr self_tp() = 0;
+        }; /*SelfTagging*/
+    } /*namespace reflect*/
 } /*namespace xo*/
 
 /* end SelfTagging.hpp */