diff --git a/CMakeLists.txt b/CMakeLists.txt
index 19aafc9f73..30489b2b23 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -11,7 +11,7 @@ project (PIO C Fortran)
 # The project version number.
 set(VERSION_MAJOR   2   CACHE STRING "Project major version number.")
 set(VERSION_MINOR   5   CACHE STRING "Project minor version number.")
-set(VERSION_PATCH   3   CACHE STRING "Project patch version number.")
+set(VERSION_PATCH   4   CACHE STRING "Project patch version number.")
 mark_as_advanced(VERSION_MAJOR VERSION_MINOR VERSION_PATCH)
 
 # Create version info in autotools parlance for pio_meta.h.
diff --git a/configure.ac b/configure.ac
index 384300af05..b9469c51dc 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2,7 +2,7 @@
 ## Ed Hartnett 8/16/17
 
 # Initialize autoconf and automake.
-AC_INIT(pio, 2.5.3)
+AC_INIT(pio, 2.5.4)
 AC_CONFIG_SRCDIR(src/clib/pio_darray.c)
 AM_INIT_AUTOMAKE([foreign serial-tests])
 
@@ -11,7 +11,7 @@ AM_INIT_AUTOMAKE([foreign serial-tests])
 # AC_DEFINE_UNQUOTED for config.h.
 AC_SUBST([PIO_VERSION_MAJOR]) PIO_VERSION_MAJOR=2
 AC_SUBST([PIO_VERSION_MINOR]) PIO_VERSION_MINOR=5
-AC_SUBST([PIO_VERSION_PATCH]) PIO_VERSION_PATCH=3
+AC_SUBST([PIO_VERSION_PATCH]) PIO_VERSION_PATCH=4
 AC_DEFINE_UNQUOTED([PIO_VERSION_MAJOR], [$PIO_VERSION_MAJOR], [PIO major version])
 AC_DEFINE_UNQUOTED([PIO_VERSION_MINOR], [$PIO_VERSION_MINOR], [PIO minor version])
 AC_DEFINE_UNQUOTED([PIO_VERSION_PATCH], [$PIO_VERSION_PATCH], [PIO patch version])
diff --git a/src/clib/Makefile.am b/src/clib/Makefile.am
index 4d21f3a838..ab9468e9fa 100644
--- a/src/clib/Makefile.am
+++ b/src/clib/Makefile.am
@@ -13,7 +13,7 @@ endif # BUILD_NCINT
 # These linker flags specify libtool version info.
 # See http://www.gnu.org/software/libtool/manual/libtool.html#Libtool-versioning
 # for information regarding incrementing `-version-info`.
-libpioc_la_LDFLAGS = -version-info 6:0:1
+libpioc_la_LDFLAGS = -version-info 7:0:2
 
 # The library header file will be installed in include dir.
 include_HEADERS = pio.h uthash.h pio_meta.h
diff --git a/src/flib/Makefile.am b/src/flib/Makefile.am
index 2117d4e7be..d7d065ae87 100644
--- a/src/flib/Makefile.am
+++ b/src/flib/Makefile.am
@@ -10,7 +10,7 @@ lib_LTLIBRARIES = libpiof.la
 # These linker flags specify libtool version info.
 # See http://www.gnu.org/software/libtool/manual/libtool.html#Libtool-versioning
 # for information regarding incrementing `-version-info`.
-libpiof_la_LDFLAGS = -version-info 5:0:1
+libpiof_la_LDFLAGS = -version-info 6:0:2
 
 # The library soure files.
 libpiof_la_LIBADD = libpio_nf.la libpio_kinds.la libpio_support.la	\