diff --git a/lib/plist.c b/lib/plist.c
index a1289801c..87d46a105 100644
--- a/lib/plist.c
+++ b/lib/plist.c
@@ -894,7 +894,7 @@ vty_prefix_list_install (struct vty *vty, afi_t afi, const char *name,
   struct prefix_list *plist;
   struct prefix_list_entry *pentry;
   struct prefix_list_entry *dup;
-  struct prefix p;
+  struct prefix p, p_tmp;
   int any = 0;
   int seqnum = -1;
   int lenum = 0;
@@ -940,6 +940,11 @@ vty_prefix_list_install (struct vty *vty, afi_t afi, const char *name,
 	  vty_out (vty, "%% Malformed IPv4 prefix%s", VTY_NEWLINE);
 	  return CMD_WARNING;
 	}
+
+      /* make a copy to verify prefix matches mask length */
+      prefix_copy (&p_tmp, &p);
+      apply_mask_ipv4 ((struct prefix_ipv4 *) &p_tmp);
+
       break;
     case AFI_IP6:
       if (strncmp ("any", prefix, strlen (prefix)) == 0)
@@ -957,9 +962,26 @@ vty_prefix_list_install (struct vty *vty, afi_t afi, const char *name,
 	  vty_out (vty, "%% Malformed IPv6 prefix%s", VTY_NEWLINE);
 	  return CMD_WARNING;
 	}
+
+      /* make a copy to verify prefix matches mask length */
+      prefix_copy (&p_tmp, &p);
+      apply_mask_ipv6 ((struct prefix_ipv6 *) &p_tmp);
+
       break;
     }
 
+  /* If prefix has bits not under the mask, adjust it to fit */
+  if (!prefix_same (&p_tmp, &p))
+    {
+      char buf[PREFIX2STR_BUFFER];
+      char buf_tmp[PREFIX2STR_BUFFER];
+      prefix2str(&p, buf, sizeof(buf));
+      prefix2str(&p_tmp, buf_tmp, sizeof(buf_tmp));
+      zlog_warn ("Prefix-list %s prefix changed from %s to %s to match length",
+                 name, buf, buf_tmp);
+      p = p_tmp;
+    }
+
   /* ge and le check. */
   if (genum && (genum <= p.prefixlen))
     return vty_invalid_prefix_range (vty, prefix);
@@ -985,14 +1007,6 @@ vty_prefix_list_install (struct vty *vty, afi_t afi, const char *name,
   if (dup)
     {
       prefix_list_entry_free (pentry);
-      vty_out (vty, "%% Insertion failed - prefix-list entry exists:%s",
-	       VTY_NEWLINE);
-      vty_out (vty, "   seq %u %s %s", dup->seq, typestr, prefix);
-      if (! any && genum)
-	vty_out (vty, " ge %d", genum);
-      if (! any && lenum)
-	vty_out (vty, " le %d", lenum);
-      vty_out (vty, "%s", VTY_NEWLINE);
       return CMD_SUCCESS;
     }