--- /dev/null
+--- a/libgomp/config/posix/time.c
++++ b/libgomp/config/posix/time.c
+@@ -29,6 +29,8 @@
+ The following implementation uses the most simple POSIX routines.
+ If present, POSIX 4 clocks should be used instead. */
+
++#define _POSIX_C_SOURCE 199309L /* for clocks */
++
+ #include "libgomp.h"
+ #include <unistd.h>
+ #if TIME_WITH_SYS_TIME