diff --git a/isisd/isis_zebra.c b/isisd/isis_zebra.c
index a1a5bea..4acaf8e 100644
--- a/isisd/isis_zebra.c
+++ b/isisd/isis_zebra.c
@@ -529,6 +529,7 @@
   struct prefix *p_generic = (struct prefix*)&p;
   unsigned long ifindex __attribute__ ((unused));
   struct in_addr nexthop __attribute__ ((unused));
+  unsigned char plength = 0;
 
   stream = zclient->ibuf;
   memset(&api, 0, sizeof(api));
@@ -541,7 +542,8 @@
   api.message = stream_getc (stream);
 
   p.family = AF_INET;
-  p.prefixlen = MIN(IPV4_MAX_PREFIXLEN, stream_getc (stream));
+  plength = stream_getc (stream);
+  p.prefixlen = MIN(IPV4_MAX_PREFIXLEN, plength);
   stream_get (&p.prefix, stream, PSIZE (p.prefixlen));
 
   if (CHECK_FLAG (api.message, ZAPI_MESSAGE_NEXTHOP))