diff -r 404c18183801 -r d0aa9e0a6d04 configure.ac
--- a/configure.ac	Wed Feb 01 13:00:40 2012 +0000
+++ b/configure.ac	Thu Feb 09 20:42:08 2012 +0000
@@ -33,6 +33,15 @@
 AC_SYS_LARGEFILE
 AM_PROG_CC_C_O
 
+AC_ARG_ENABLE([atomic],
+	      [AS_HELP_STRING([--disable-atomic],
+	      		      [disable atomic transactions])],
+	      [],
+	      [enable_atomic=yes])
+if test "$enable_atomic" = "yes"; then
+    AC_DEFINE([ENABLE_ATOMIC],[1],[Define if atomic transactions are wanted.])
+fi
+
 AC_MSG_CHECKING([for Microsoft Windows native API])
 case $host_os in
     *mingw*)	AC_DEFINE([MSWIN_API], 1,
@@ -45,7 +54,7 @@
 AM_CONDITIONAL(MSWIN_API, test "$mswin_api" = "yes")
 AC_SUBST(EXTRA_LIBS)
 
-if test "$mswin_api" = "yes"; then
+if test "$enable_atomic" = "yes" -a "$mswin_api" = "yes"; then
     AC_MSG_CHECKING([for Microsoft Windows Kernel Transaction Manager])
     save_LIBS="$LIBS"
     LIBS="-lktmw32 $LIBS"