Index: configure.ac
===================================================================
--- configure.ac	(revision 246862)
+++ configure.ac	(working copy)
@@ -631,6 +631,15 @@
 	AC_MSG_RESULT(unknown)
 )
 
+AC_MSG_CHECKING([if your system has the uint64_t type defined])
+AC_COMPILE_IFELSE(
+	AC_LANG_PROGRAM([#include <sys/types.h>],
+		[uint64_t foo = 1]),
+	AC_DEFINE([HAVE_UINT64_T], 1, [Define to 1 if your C compiler recognizes the uint64_t data type.])
+	AC_MSG_RESULT(yes),
+	AC_MSG_RESULT(no)
+)
+
 AST_GCC_ATTRIBUTE(pure)
 AST_GCC_ATTRIBUTE(malloc)
 AST_GCC_ATTRIBUTE(const)