diff --git a/include/sys/time.h b/include/sys/time.h
index b6787c3c..bfe1414e 100644
--- a/include/sys/time.h
+++ b/include/sys/time.h
@@ -51,6 +51,17 @@ int adjtime (const struct timeval *, struct timeval *);
 	((a)->tv_usec += 1000000, (a)->tv_sec--) )
 #endif
 
+#if defined(_GNU_SOURCE)
+#define TIMEVAL_TO_TIMESPEC(tv, ts) ( \
+	(ts)->tv_sec = (tv)->tv_sec, \
+	(ts)->tv_nsec = (tv)->tv_usec * 1000, \
+	(void)0 )
+#define TIMESPEC_TO_TIMEVAL(tv, ts) ( \
+	(tv)->tv_sec = (ts)->tv_sec, \
+	(tv)->tv_usec = (ts)->tv_nsec / 1000, \
+	(void)0 )
+#endif
+
 #ifdef __cplusplus
 }
 #endif