diff --git a/doc/conf.py b/doc/conf.py
index 9d2a89fc..ef89adf6 100644
--- a/doc/conf.py
+++ b/doc/conf.py
@@ -141,9 +141,9 @@ def load_res():
 # built documents.
 #
 # The short X.Y version.
-version = '1.3.5'
+version = '1.4.0'
 # The full version, including alpha/beta/rc tags.
-release = '1.3.5'
+release = '1.4.0'
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.
diff --git a/setup.py b/setup.py
index f92df5ea..f4feb120 100644
--- a/setup.py
+++ b/setup.py
@@ -157,7 +157,8 @@
 Python 2 and 3
 --------------
 
-The code can run in both Python branches without any modification.
+The code should run in both Python branches without any modification, although
+compatibility with Python 2 is not checked any longer.
 
 Get xrt
 -------
@@ -179,7 +180,7 @@
 
 setup(
     name='xrt',
-    version='1.3.5',
+    version='1.4.0',
     description='Ray tracing and wave propagation in x-ray regime, primarily '
                 'meant for modeling synchrotron sources, beamlines and '
                 'beamline elements. Includes a GUI for creating a beamline '
diff --git a/xrt/__init__.py b/xrt/__init__.py
index defb9c32..d123e460 100644
--- a/xrt/__init__.py
+++ b/xrt/__init__.py
@@ -146,7 +146,8 @@
 Python 2 and 3
 --------------
 
-The code can run in both Python branches without any modification.
+The code should run in both Python branches without any modification, although
+compatibility with Python 2 is not checked any longer.
 
 Dependencies
 ------------
@@ -211,10 +212,11 @@
 initiated the custom field undulator project and supplied tables of magnetic
 field. Bernard Kozioziemski (LLNL) has pointed to the importance of considering
 the *total* absorption cross-section (not just photoelectric absorption) in the
-cases of light materials at high energy. Emilio Heredia (CLS) is thanked for
-valuable suggestions on GUI. Tim May (CLS) is acknowledged for inspiring the
-custom magnetic field calculation development, providing field tables and
-comparing the results with other codes.
+cases of light materials at high energy. He also did deep tests of the mosaic
+crystal model. Emilio Heredia (CLS) is thanked for valuable suggestions on GUI.
+Tim May (CLS) is acknowledged for inspiring the custom magnetic field
+calculation development, providing field tables and comparing the results with
+other codes.
 
 """
 
diff --git a/xrt/version.py b/xrt/version.py
index 7a9833e2..10b16268 100644
--- a/xrt/version.py
+++ b/xrt/version.py
@@ -1,4 +1,4 @@
 # -*- coding: utf-8 -*-
-__versioninfo__ = (1, 3, 5)
+__versioninfo__ = (1, 4, 0)
 __version__ = '.'.join(map(str, __versioninfo__))
-__date__ = "19 Nov 2020"
+__date__ = "22 Sep 2021"