diff --git a/CMakeLists.txt b/CMakeLists.txt
index b20944e4..ef39bd5c 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,7 +1,7 @@
 cmake_minimum_required(VERSION 3.6...3.14)
 message(STATUS "CMake version: " ${CMAKE_VERSION})
 project(TeNeS CXX)
-set(TENES_VERSION 2.1.0)
+set(TENES_VERSION 2.2-dev)
 
 set(CMAKE_CXX_STANDARD 11)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
diff --git a/docs/sphinx/en/conf.py b/docs/sphinx/en/conf.py
index ce0b54d9..9107abd2 100644
--- a/docs/sphinx/en/conf.py
+++ b/docs/sphinx/en/conf.py
@@ -55,9 +55,9 @@
 # built documents.
 #
 # The short X.Y version.
-version = u'2.1'
+version = u'2.2'
 # The full version, including alpha/beta/rc tags.
-release = u'2.1.0'
+release = u'2.2-dev'
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.
diff --git a/docs/sphinx/ja/conf.py b/docs/sphinx/ja/conf.py
index a8dfe9db..7b254b5b 100644
--- a/docs/sphinx/ja/conf.py
+++ b/docs/sphinx/ja/conf.py
@@ -55,9 +55,9 @@
 # built documents.
 #
 # The short X.Y version.
-version = u'2.1'
+version = u'2.2'
 # The full version, including alpha/beta/rc tags.
-release = u'2.1.0'
+release = u'2.2-dev'
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.
diff --git a/src/version.hpp b/src/version.hpp
index 0d8c2ed0..a8869c90 100644
--- a/src/version.hpp
+++ b/src/version.hpp
@@ -17,6 +17,6 @@
 #ifndef TENES_SRC_VERSION_HPP_
 #define TENES_SRC_VERSION_HPP_
 
-#define TENES_VERSION "2.1.0"
+#define TENES_VERSION "2.2-dev"
 
 #endif // TENES_SRC_VERSION_HPP_
diff --git a/tool/tenes_simple.py b/tool/tenes_simple.py
index 51d272b8..58f7f551 100644
--- a/tool/tenes_simple.py
+++ b/tool/tenes_simple.py
@@ -1349,7 +1349,7 @@ def tenes_simple(
         help="Save onsite terms as site Hamiltonians",
     )
     parser.add_argument(
-        "-v", "--version", dest="version", action="version", version="2.1.0"
+        "-v", "--version", dest="version", action="version", version="2.2-dev"
     )
 
     args = parser.parse_args()
diff --git a/tool/tenes_std.py b/tool/tenes_std.py
index 4bb6468b..0f8ef803 100644
--- a/tool/tenes_std.py
+++ b/tool/tenes_std.py
@@ -1272,7 +1272,7 @@ def to_toml(self, f: TextIO):
         "-o", "--output", dest="output", default="input.toml", help="Output TOML file"
     )
     parser.add_argument(
-        "-v", "--version", dest="version", action="version", version="2.1.0"
+        "-v", "--version", dest="version", action="version", version="2.2-dev"
     )
 
     args = parser.parse_args()