diff --git a/configure.ac b/configure.ac
index 181a4e8..0ecc29c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -16,6 +16,8 @@ AC_PROG_CC_C99
 AC_USE_SYSTEM_EXTENSIONS
 AC_SEARCH_LIBS([getaddrinfo], [resolv nsl])
 AC_SEARCH_LIBS([socket], [socket])
+AC_CHECK_LIB([rt], [clock_gettime])
+AC_CHECK_FUNCS([clock_gettime])
 PKG_CHECK_MODULES([libsodium], [libsodium >= 1.0.4])
 AC_CONFIG_FILES([Makefile])
 AC_OUTPUT