diff --git a/CMakeLists.txt b/CMakeLists.txt
index 19ec3ee614d..856a6f160e4 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -5,7 +5,7 @@ project (PIO C Fortran)
 # The project version number.
 set(VERSION_MAJOR   2   CACHE STRING "Project major version number.")
 set(VERSION_MINOR   4   CACHE STRING "Project minor version number.")
-set(VERSION_PATCH   3   CACHE STRING "Project patch version number.")
+set(VERSION_PATCH   4-development   CACHE STRING "Project patch version number.")
 mark_as_advanced(VERSION_MAJOR VERSION_MINOR VERSION_PATCH)
 
 # The size of the data buffer for write/read_darray().
diff --git a/configure.ac b/configure.ac
index 99b4a7f93db..8e490f13971 100644
--- a/configure.ac
+++ b/configure.ac
@@ -3,19 +3,19 @@
 
 
 # Initialize autoconf and automake.
-AC_INIT(pio, 2.4.3)
+AC_INIT(pio, 2.4.4-development)
 AC_CONFIG_SRCDIR(src/clib/pio_darray.c)
 AM_INIT_AUTOMAKE([foreign serial-tests])
 
 # The PIO version, again.
 AC_DEFINE([PIO_VERSION_MAJOR], [2], [PIO major version])
 AC_DEFINE([PIO_VERSION_MINOR], [4], [PIO minor version])
-AC_DEFINE([PIO_VERSION_PATCH], [3], [PIO patch version])
+AC_DEFINE([PIO_VERSION_PATCH], [4-development], [PIO patch version])
 
 # Once more for the documentation.
 AC_SUBST([VERSION_MAJOR], [2])
 AC_SUBST([VERSION_MINOR], [4])
-AC_SUBST([VERSION_PATCH], [3])
+AC_SUBST([VERSION_PATCH], [4-development])
 
 # The m4 directory holds macros for autoconf.
 AC_CONFIG_MACRO_DIR([m4])