diff --git a/.gitignore b/.gitignore
index b290779..89ab317 100644
--- a/.gitignore
+++ b/.gitignore
@@ -32,5 +32,6 @@ examples/strdiff_cp
 examples/strdiff_storage
 examples/unidiff
 examples/unistrdiff
+include/dtl/variables.hpp
 test/*/*/*_
 test/strdiff3_test
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 42739e3..1bbb9d2 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,9 +1,11 @@
 cmake_minimum_required(VERSION 3.20)
 cmake_policy(SET CMP0048 NEW)
 
+set(DTL_VERSION 2.01)
+
 project(
   dtl
-  VERSION 1.21
+  VERSION ${DTL_VERSION}
 )
 
 include(CheckIncludeFile)
@@ -18,6 +20,12 @@ if(HAVE_UNISTD_H)
   add_definitions(-DHAVE_UNISTD_H)
 endif()
 
+configure_file(
+  ${CMAKE_CURRENT_SOURCE_DIR}/include/dtl/variables.hpp.in
+  ${CMAKE_CURRENT_SOURCE_DIR}/include/dtl/variables.hpp
+  @ONLY
+)
+
 include_directories(BEFORE ${CMAKE_CURRENT_SOURCE_DIR}/include)
 
 option(DTL_ENABLE_TESTING "Enable DTL unit tests" OFF)
diff --git a/ChangeLog b/ChangeLog
index 1580f34..6b2f35d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -13,7 +13,7 @@
   * pr: initialize variables
     * https://github.com/cubicdaiya/dtl/pull/16
 
-  * 1.21 released
+  * 2.01 released
 
 2022-04-11 Tatsuhiko Kubo <cubicdaiya@gmail.com>
 
diff --git a/include/dtl/variables.hpp b/include/dtl/variables.hpp.in
similarity index 99%
rename from include/dtl/variables.hpp
rename to include/dtl/variables.hpp.in
index e93f843..09621d9 100644
--- a/include/dtl/variables.hpp
+++ b/include/dtl/variables.hpp.in
@@ -63,7 +63,7 @@ using std::vector;
 /**
  * version string
  */
-const string version = "1.21";
+const string version = "@DTL_VERSION@";
 
 /**
  * type of edit for SES