diff --git a/lib/if.c b/lib/if.c
index b61bdbf..86f754b 100644
--- a/lib/if.c
+++ b/lib/if.c
@@ -664,7 +664,7 @@
       strncat (logbuf, inet_ntop (p->family, &p->u.prefix, buf, BUFSIZ),
 	       BUFSIZ - strlen(logbuf));
     }
-  zlog (NULL, LOG_INFO, logbuf);
+  zlog (NULL, LOG_INFO, "%s", logbuf);
 }
 
 /* If two connected address has same prefix return 1. */