diff --git a/lib/plist.c b/lib/plist.c
index 7416ebd..6107556 100644
--- a/lib/plist.c
+++ b/lib/plist.c
@@ -733,16 +733,16 @@
 #endif /* HAVE_IPV6 */
 
   /* ge and le check. */
-  if (genum && genum <= p.prefixlen)
+  if (genum && (genum <= p.prefixlen))
     return vty_invalid_prefix_range (vty, prefix);
 
-  if (lenum && lenum <= p.prefixlen)
+  if (lenum && (lenum <= p.prefixlen))
     return vty_invalid_prefix_range (vty, prefix);
 
-  if (lenum && genum > lenum)
+  if (lenum && (genum > lenum))
     return vty_invalid_prefix_range (vty, prefix);
 
-  if (genum && lenum == (afi == AFI_IP ? 32 : 128))
+  if (genum && (lenum == (afi == AFI_IP ? 32 : 128)))
     lenum = 0;
 
   /* Get prefix_list with name. */