diff --git a/v2_0_cpp_adaptor.md b/v2_0_cpp_adaptor.md
index f7883aa..0d81c67 100644
--- a/v2_0_cpp_adaptor.md
+++ b/v2_0_cpp_adaptor.md
@@ -41,6 +41,7 @@ msgpack-c provides predefined adaptors for C++ primitive types and standard libr
 | v4raw_ref *3      | str                         |since 1.2.0|
 | ext               | ext                         |    |
 | ext_ref *3        | ext                         |    |
+| variant           | any type                    |since 1.2.0, boost is required|
 
 | C++11 type         | msgpack::object type        |note|
 |:------------------ |:--------------------------- |:---|