diff --git a/src/libstrongswan/utils/utils.h b/src/libstrongswan/utils/utils.h
index 46eaf7b64..8637c3c82 100644
--- a/src/libstrongswan/utils/utils.h
+++ b/src/libstrongswan/utils/utils.h
@@ -507,7 +507,7 @@ time_t time_monotonic(timeval_t *tv);
 static inline void timeval_add_ms(timeval_t *tv, u_int ms)
 {
 	tv->tv_usec += ms * 1000;
-	while (tv->tv_usec > 1000000 /* 1s */)
+	while (tv->tv_usec >= 1000000 /* 1s */)
 	{
 		tv->tv_usec -= 1000000;
 		tv->tv_sec++;