diff --git a/CMakeLists.txt b/CMakeLists.txt
index a0b8d359f08..47060767215 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -14,7 +14,7 @@ set(PIO_VERSION_MINOR ${VERSION_MINOR})
 set(PIO_VERSION_PATCH ${VERSION_PATCH})
 
 # This is needed for the libpio.settings file.
-SET(PACKAGE_VERSION ${VERSION})
+SET(PACKAGE_VERSION ${PIO_VERSION_MAJOR}.${PIO_VERSION_MINOR}.${PIO_VERSION_PATCH})
 
 # Determine the configure date.
 IF(DEFINED ENV{SOURCE_DATE_EPOCH})
diff --git a/configure.ac b/configure.ac
index 069112ee79a..ba66ce7a2a9 100644
--- a/configure.ac
+++ b/configure.ac
@@ -6,15 +6,19 @@ AC_INIT(pio, 2.5.1-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], [5], [PIO minor version])
-AC_DEFINE([PIO_VERSION_PATCH], [1], [PIO patch version])
+# The PIO version, again. Use AC_SUBST for pio_meta.h and
+# 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=1
+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])
 
 # Once more for the documentation.
 AC_SUBST([VERSION_MAJOR], [2])
 AC_SUBST([VERSION_MINOR], [5])
-AC_SUBST([VERSION_PATCH], [1-development])
+AC_SUBST([VERSION_PATCH], [1])
 
 # The m4 directory holds macros for autoconf.
 AC_CONFIG_MACRO_DIR([m4])
@@ -349,7 +353,7 @@ AC_DEFUN([AX_SET_META],[
 #####
 # Define values used in include/pio_meta.h
 #####
-AX_SET_META([PIO_HAS_SZIP],[$have_szip_write],[yes])
+AX_SET_META([PIO_HAS_SZIP_WRITE],[$have_szip_write],[yes])
 AX_SET_META([PIO_HAS_PNETCDF],[$enable_pnetcdf],[yes])
 AX_SET_META([PIO_HAS_PAR_FILTERS], [$have_par_filters],[yes])
 
@@ -403,3 +407,5 @@ AC_OUTPUT(Makefile
 
 # Show the build summary.
 cat libpio.settings
+
+
diff --git a/src/clib/pio_meta.h.in b/src/clib/pio_meta.h.in
index 6fae3f05960..1729254398c 100644
--- a/src/clib/pio_meta.h.in
+++ b/src/clib/pio_meta.h.in
@@ -21,7 +21,7 @@
 #define PIO_VERSION_MAJOR @PIO_VERSION_MAJOR@ /*!< pio-c major version. */
 #define PIO_VERSION_MINOR @PIO_VERSION_MINOR@ /*!< pio-c minor version. */
 #define PIO_VERSION_PATCH @PIO_VERSION_PATCH@ /*!< pio-c patch version. */
-#define PIO_VERSION       "@VERSION@"
+#define PIO_VERSION       "@PACKAGE_VERSION@"
 
 #define PIO_HAS_SZIP_WRITE @PIO_HAS_SZIP_WRITE@ /*!< szip write support */
 #define PIO_HAS_PNETCDF   @PIO_HAS_PNETCDF@ /*!< PnetCDF support. */