diff --git a/ase/configure b/ase/configure
index 5522e44e..f665f3e2 100755
--- a/ase/configure
+++ b/ase/configure
@@ -850,8 +850,9 @@ if test -n "$ac_init_help"; then
 Optional Features:
   --disable-FEATURE       do not include FEATURE (same as --enable-FEATURE=no)
   --enable-FEATURE[=ARG]  include FEATURE [ARG=yes]
---enable-wchar user wchar_t a default charater type
---enable-reentrant defined _REENTRANT
+  --enable-wchar          use wchar_t a default charater type when enabled
+                          (default. yes)
+  --enable-reentrant      define _REENTRANT (default. yes)
 
 Some influential environment variables:
   CXX         C++ compiler command
@@ -10815,11 +10816,11 @@ _ACEOF
 # Check whether --enable-wchar or --disable-wchar was given.
 if test "${enable_wchar+set}" = set; then
   enableval="$enable_wchar"
-  wchar_is=$enableval
+  enable_wchar_is=$enableval
 else
-  wchar_is=yes
+  enable_wchar_is=yes
 fi;
-if test "$wchar_is" = "yes"
+if test "$enable_wchar_is" = "yes"
 then
 
 cat >>confdefs.h <<\_ACEOF
@@ -10837,11 +10838,11 @@ fi
 # Check whether --enable-reentrant or --disable-reentrant was given.
 if test "${enable_reentrant+set}" = set; then
   enableval="$enable_reentrant"
-  reentrant_is=$enableval
+  enable_reentrant_is=$enableval
 else
-  reentrant_is=yes
+  enable_reentrant_is=yes
 fi;
-if test "$reentrant_is" = "yes"
+if test "$enable_reentrant_is" = "yes"
 then
 	CFLAGS="$CFLAGS -D_REENTRANT -D_THREAD_SAFE"
 fi
diff --git a/ase/configure.ac b/ase/configure.ac
index 7af9b3e9..78a2dc70 100644
--- a/ase/configure.ac
+++ b/ase/configure.ac
@@ -1,6 +1,6 @@
 AC_PREREQ(2.53)
 AC_INIT([xpkit], [deb-0.1.0])
-AC_REVISION([$Revision: 1.48 $])
+AC_REVISION([$Revision: 1.49 $])
 AC_CONFIG_HEADER([xp/config.h])
 
 # Checks for programs.
@@ -59,20 +59,20 @@ AC_CHECK_SIZEOF(long double)
 #AC_FUNC_REALLOC
 #AC_CHECK_FUNCS([memset])
 
-AC_ARG_ENABLE(wchar, 
-	[--enable-wchar user wchar_t a default charater type],
-	wchar_is=$enableval,wchar_is=yes)
-if test "$wchar_is" = "yes"
+AC_ARG_ENABLE([wchar], [AC_HELP_STRING([--enable-wchar],
+	[use wchar_t a default charater type when enabled (default. yes)])],
+	enable_wchar_is=$enableval,enable_wchar_is=yes)
+if test "$enable_wchar_is" = "yes"
 then
 	AC_DEFINE([XP_CHAR_IS_WCHAR],[],[char is wchar])
 else
 	AC_DEFINE([XP_CHAR_IS_MCHAR],[],[char is mchar])
 fi
 
-AC_ARG_ENABLE(reentrant,
-	[--enable-reentrant defined _REENTRANT],
-	reentrant_is=$enableval,reentrant_is=yes)
-if test "$reentrant_is" = "yes"
+AC_ARG_ENABLE([reentrant], [AC_HELP_STRING([--enable-reentrant],
+	[define _REENTRANT (default. yes)])],
+	enable_reentrant_is=$enableval,enable_reentrant_is=yes)
+if test "$enable_reentrant_is" = "yes"
 then
 	[CFLAGS="$CFLAGS -D_REENTRANT -D_THREAD_SAFE"]
 fi