diff --git a/CMakeLists.txt b/CMakeLists.txt
index 87be383..d9ca4df 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -2,6 +2,14 @@ cmake_minimum_required(VERSION 2.6...3.0.2)
 
 project(xbyak_riscv LANGUAGES CXX VERSION 6.68)
 
+OPTION(XBYAK_RISCV_V "RISC-V 'V' Vector Extension support" OFF)
+
+IF(XBYAK_RISCV_V)
+	ADD_DEFINITIONS(-DXBYAK_RISCV_V)
+ENDIF()
+
+message(XBYAK_RISCV_V=${XBYAK_RISCV_V})
+
 file(GLOB headers xbyak_riscv/*.h)
 
 if (DEFINED CMAKE_VERSION AND CMAKE_VERSION VERSION_GREATER_EQUAL 3.0.2)
diff --git a/readme.md b/readme.md
index c115413..7c55c1a 100644
--- a/readme.md
+++ b/readme.md
@@ -32,7 +32,14 @@ Install QEMU and C++ compiler for RISC-V.
 sudo apt install g++-12-riscv64-linux-gnu
 make -C sample
 ```
-
+Generate targets:
+```
+cmake -DCMAKE_BUILD_TYPE=Debug -DXBYAK_RISCV_V=ON ..
+```
+Build:
+```
+make --build .  --parallel 4
+```
 
 ## License