diff --git a/configure.in b/configure.in
index 914302d1c..706e8e376 100644
--- a/configure.in
+++ b/configure.in
@@ -551,7 +551,7 @@ AC_CHECK_FUNCS(valloc)
 
 AC_CHECK_FUNCS(atexit on_exit)
 
-AC_CHECK_FUNCS(timegm)
+AC_CHECK_FUNCS(timegm gmtime_r)
 
 AC_CHECK_SIZEOF(char)
 AC_CHECK_SIZEOF(short)