diff --git a/config/opal_check_compiler_version.m4 b/config/opal_check_compiler_version.m4
index f6e6dfb29b..f914af53c9 100644
--- a/config/opal_check_compiler_version.m4
+++ b/config/opal_check_compiler_version.m4
@@ -18,14 +18,14 @@ dnl
 #
 AC_DEFUN([OPAL_CHECK_COMPILER_VERSION_ID],
 [
-    _OPAL_CHECK_COMPILER(FAMILYID)
-    _OPAL_CHECK_COMPILER_STRINGIFY(FAMILYNAME)
-    _OPAL_CHECK_COMPILER(VERSION)
-    _OPAL_CHECK_COMPILER_STRINGIFY(VERSION_STR)
+    OPAL_CHECK_COMPILER(FAMILYID)
+    OPAL_CHECK_COMPILER_STRINGIFY(FAMILYNAME)
+    OPAL_CHECK_COMPILER(VERSION)
+    OPAL_CHECK_COMPILER_STRINGIFY(VERSION_STR)
 ])dnl
 
 
-AC_DEFUN([_OPAL_CHECK_COMPILER], [
+AC_DEFUN([OPAL_CHECK_COMPILER], [
     lower=m4_tolower($1)
     AC_CACHE_CHECK([for compiler $lower], opal_cv_compiler_[$1],
     [
@@ -56,7 +56,7 @@ int main (int argc, char * argv[])
 ])dnl
 
 
-AC_DEFUN([_OPAL_CHECK_COMPILER_STRINGIFY], [
+AC_DEFUN([OPAL_CHECK_COMPILER_STRINGIFY], [
     lower=m4_tolower($1)
     AC_CACHE_CHECK([for compiler $lower], opal_cv_compiler_[$1],
     [
diff --git a/config/opal_configure_options.m4 b/config/opal_configure_options.m4
index 1a1b04316f..8bd312c4f1 100644
--- a/config/opal_configure_options.m4
+++ b/config/opal_configure_options.m4
@@ -502,24 +502,24 @@ fi
 #
 
 # No lower and upper bound required or enforced
-_OPAL_WITH_OPTION_MIN_MAX_VALUE(processor_name,  256,  16, 1024)
+OPAL_WITH_OPTION_MIN_MAX_VALUE(processor_name,  256,  16, 1024)
 
 # Min length according to information passed in ompi/errhandler/errcode.c
-_OPAL_WITH_OPTION_MIN_MAX_VALUE(error_string,    256,  64, 1024)
+OPAL_WITH_OPTION_MIN_MAX_VALUE(error_string,    256,  64, 1024)
 
 # Min length according to MPI-2.1, p. 236 (information passed in ompi/communicator/comm.c: min only 48)
-_OPAL_WITH_OPTION_MIN_MAX_VALUE(object_name,      64,  64,  256)
+OPAL_WITH_OPTION_MIN_MAX_VALUE(object_name,      64,  64,  256)
 
 # Min and Max length according to MPI-2.1, p. 287 is 32; longest key in ROMIO however 33
-_OPAL_WITH_OPTION_MIN_MAX_VALUE(info_key,         36,  33,  255)
+OPAL_WITH_OPTION_MIN_MAX_VALUE(info_key,         36,  34,  255)
 
 # No lower and upper bound required or enforced!
-_OPAL_WITH_OPTION_MIN_MAX_VALUE(info_val,        256,  32, 1024)
+OPAL_WITH_OPTION_MIN_MAX_VALUE(info_val,        256,  32, 1024)
 
 # Min length according to _POSIX_HOST_NAME_MAX=255 (4*HOST_NAME_MAX)
-_OPAL_WITH_OPTION_MIN_MAX_VALUE(port_name,      1024, 255, 2048)
+OPAL_WITH_OPTION_MIN_MAX_VALUE(port_name,      1024, 255, 2048)
 
 # Min length accroding to MPI-2.1, p. 418
-_OPAL_WITH_OPTION_MIN_MAX_VALUE(datarep_string,  128,  64,  256)
+OPAL_WITH_OPTION_MIN_MAX_VALUE(datarep_string,  128,  64,  256)
 
 ])dnl
diff --git a/config/opal_functions.m4 b/config/opal_functions.m4
index f967b2e516..4c327f0142 100644
--- a/config/opal_functions.m4
+++ b/config/opal_functions.m4
@@ -365,12 +365,12 @@ dnl #######################################################################
 dnl #######################################################################
 
 #
-# _OPAL_WITH_OPTION_MIN_MAX_VALUE(NAME,DEFAULT_VALUE,LOWER_BOUND,UPPER_BOUND)
+# OPAL_WITH_OPTION_MIN_MAX_VALUE(NAME,DEFAULT_VALUE,LOWER_BOUND,UPPER_BOUND)
 # Defines a variable OPAL_MAX_xxx, with "xxx" being specified as parameter $1 as "variable_name".
 # If not set at configure-time using --with-max-xxx, the default-value ($2) is assumed.
 # If set, value is checked against lower (value >= $3) and upper bound (value <= $4)
 #
-AC_DEFUN([_OPAL_WITH_OPTION_MIN_MAX_VALUE], [
+AC_DEFUN([OPAL_WITH_OPTION_MIN_MAX_VALUE], [
     max_value=[$2]
     AC_MSG_CHECKING([maximum length of ]m4_translit($1, [_], [ ]))
     AC_ARG_WITH([max-]m4_translit($1, [_], [-]),
@@ -393,5 +393,6 @@ AC_DEFUN([_OPAL_WITH_OPTION_MIN_MAX_VALUE], [
     AC_MSG_RESULT([$max_value])
     AC_DEFINE_UNQUOTED([OPAL_MAX_]m4_toupper($1), $max_value,
                        [Maximum length of ]m4_translit($1, [_], [ ])[s (default is $2)])
+    [OPAL_MAX_]m4_toupper($1)=$max_value
     AC_SUBST([OPAL_MAX_]m4_toupper($1))
 ])dnl
diff --git a/ompi/mca/io/romio/romio/README_OMPI b/ompi/mca/io/romio/romio/README_OMPI
index 4c0fdf79b9..3af505cf11 100644
--- a/ompi/mca/io/romio/romio/README_OMPI
+++ b/ompi/mca/io/romio/romio/README_OMPI
@@ -18,5 +18,7 @@ Local modifications:
   versions of the GNU auto tools -- see comments in file.
 - Added a full set of Makefile.am files; removed all prior Makefile's;
   replaced most Makefile.in's.  Ignore mpi2-other and man directories.
+- We define MPI_MAX_DATAREP_STRING, therefore
+  protect the redefinition in include/mpio.h
 - Not all systems have snprintf(); include "opal/util/printf.h" in
   test/noncontig_coll.c