diff --git a/ChangeLog b/ChangeLog
index ff12a6f9b..3e8f4a777 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2001-10-24  Pavel Roskin  <proski@gnu.org>
+
+	* configure.in: Move AC_FUNC_MMAP before it's used indirectly.
+	Allow using --without-mmap.
+	* INSTALL: Document --without-mmap.
+
 2001-10-24  Andrew V. Samoilov  <kai@cmail.ru>
 
 	* configure.in: Resurrect ALL_LINGUAS test, to allow specify list
diff --git a/INSTALL b/INSTALL
index 29d9b55cb..8ac695522 100644
--- a/INSTALL
+++ b/INSTALL
@@ -108,8 +108,11 @@ the directory base where you installed the gpm package.
 `--with-hsc'
      Compiles support for HSC firewall into the ftp virtual file system.
 
-`--with-mmap'
-     Needed when compiling under AIX if you want the fast viewer.
+`--with-mmap', `--without-mmap'
+     Force using or not using the mmap function.  It is currently used
+     in the internal viewer.  `--with-mmap' may be useful on some
+     versions of AIX where the `configure' script decides that mmap is
+     broken, but it's actually suitable for the internal viewer.
 
 `--with-subshell[=optional]', `--without-subshell' 
      The subshell support is by default turned on, you can disable
diff --git a/configure.in b/configure.in
index c83540ac3..3b59b16a4 100644
--- a/configure.in
+++ b/configure.in
@@ -30,6 +30,25 @@ AC_CHECK_TOOL(AR, ar, ar)
 dnl Only list browsers here that can be run in background (i.e. with `&')
 AC_CHECK_PROGS(X11_WWW, [gnome-moz-remote mozilla konqueror opera netscape])
 
+dnl
+dnl Ovverriding mmap support.  This has to be before AC_FUNC_MMAP is used.
+dnl We use only part of the functionality of mmap, so on AIX,
+dnl it's possible to use mmap, even if it doesn't pass the autoconf test.
+dnl
+AC_ARG_WITH(mmap, 
+	[--with-mmap                To force using the mmap call (AIX)],
+	[case $withval in
+yes)
+	ac_cv_func_mmap_fixed_mapped=yes
+	AC_MSG_NOTICE([forcing MMAP support])
+	;;
+no)
+	ac_cv_func_mmap_fixed_mapped=no
+	AC_MSG_NOTICE([disabling MMAP support])
+	;;
+esac])
+AC_FUNC_MMAP
+
 if test x$ALL_LINGUAS = x; then
 ALL_LINGUAS="az ca cs da de el es es_ES fi fr hu it ja ko lv nl no pl pt_BR ro ru sk sl sv uk ta tr wa zh_TW zh_CN.GB2312"
 fi
@@ -189,7 +208,6 @@ AC_TYPE_PID_T
 AC_TYPE_UID_T
 AC_CHECK_TYPE(nlink_t, unsigned int)
 
-AC_FUNC_MMAP
 AC_FUNC_ALLOCA
 AC_FUNC_STRCOLL
 
@@ -492,18 +510,6 @@ AC_ARG_WITH(efence,
 	mem_debug="Electric Fence"
 fi])
 
-dnl
-dnl To force mmap support
-dnl We use only part of the functionality of mmap, so on AIX,
-dnl it's possible to use mmap, even if it doesn't pass the autoconf test.
-dnl
-AC_ARG_WITH(mmap, 
-	[--with-mmap                To force using the mmap call (AIX)],
-	[if test x$withval = xyes; then
-	AC_DEFINE(HAVE_MMAP)
-        AC_MSG_NOTICE([forcing MMAP support])
-fi])
-
 slang_check_lib=true
 slang_term=""
 slang_use_system_installed_lib=false