diff --git a/ripngd/ripng_zebra.c b/ripngd/ripng_zebra.c
index e02b098..7221616 100644
--- a/ripngd/ripng_zebra.c
+++ b/ripngd/ripng_zebra.c
@@ -134,6 +134,7 @@
   unsigned long ifindex;
   struct in6_addr nexthop;
   struct prefix_ipv6 p;
+  unsigned char plength = 0;
 
   s = zclient->ibuf;
   ifindex = 0;
@@ -147,7 +148,8 @@
   /* IPv6 prefix. */
   memset (&p, 0, sizeof (struct prefix_ipv6));
   p.family = AF_INET6;
-  p.prefixlen = MIN(IPV6_MAX_PREFIXLEN, stream_getc (s));
+  plength = stream_getc (s);
+  p.prefixlen = MIN(IPV6_MAX_PREFIXLEN, plength);
   stream_get (&p.prefix, s, PSIZE (p.prefixlen));
 
   /* Nexthop, ifindex, distance, metric. */