diff --git a/configure.in b/configure.in
index bce9a1e83..4e3d0d424 100755
--- a/configure.in
+++ b/configure.in
@@ -517,6 +517,7 @@ AC_PROG_INSTALL
 AC_PROG_RANLIB
 AC_CHECK_TOOL(AR,[ar],:)
 AC_PATH_PROG(INSTALL_INFO,install-info,true,$PATH:/sbin:/usr/sbin:/usr/etc:/usr/local/sbin)
+AC_CHECK_HEADERS(winsock.h winsock2.h)
 AC_PATH_PROG(SHELL,sh)
 AC_CHECK_TOOL([INDENT], [indent], [:])
 
@@ -1248,7 +1249,7 @@ AC_CHECK_HEADERS(sys/shm.h sys/socket.h sys/stat.h)
 AC_CHECK_HEADERS(sys/time.h sys/times.h sys/types.h)
 AC_CHECK_HEADERS(sys/ucontext.h sys/un.h sys/wait.h)
 AC_CHECK_HEADERS(time.h ucontext.h unistd.h utime.h)
-AC_CHECK_HEADERS(wctype.h winsock.h winsock2.h)
+AC_CHECK_HEADERS(wctype.h)
 AC_CHECK_HEADERS(zlib.h zutil.h)
 AC_CHECK_HEADERS(mach-o/dyld.h LibLoaderAPI.h)
 
@@ -1319,6 +1320,24 @@ AC_CHECK_SIZEOF(void *,4)
 
 AC_DEFINE_UNQUOTED(CELLSIZE, $ac_cv_sizeof_void_p, [size of a cell in bytes.])
 
+dnl check whether int64_t exists
+AC_MSG_CHECKING(whether int64_t is defined)
+AC_CACHE_VAL(yap_cv_int64_t_defined,[
+AC_TRY_RUN(
+	#include <stdint.h>
+	int main() {
+	   int64_t i;
+	   return 0;
+	}
+	,
+	yap_cv_int64_t_defined=yes,yap_cv_int64_t_defined=no,yap_cv_int64_t_defined=no)])
+AC_MSG_RESULT($yap_cv_int64_t_defined)
+if test $yap_cv_int64_t_defined = yes
+then
+  AC_DEFINE_UNQUOTED(INT64_T_DEFINED,1,[type of int64_t])
+fi
+AC_MSG_CHECKING(for int64_t)
+AC_SUBST(INT64_T_DEFINED)
 
 dnl check type of malloc (i.e. char *  or void *)
 AC_MSG_CHECKING(for type of malloc)