diff --git a/sys/net/rtsock.c b/sys/net/rtsock.c
index 3ad9ee6c9863..2a085405e689 100644
--- a/sys/net/rtsock.c
+++ b/sys/net/rtsock.c
@@ -679,6 +679,7 @@ again:
 		}
 		len += dlen;
 	}
+	len = ALIGN(len);
 	if (cp == 0 && w != NULL && !second_time) {
 		register struct walkarg *rw = w;