diff --git a/sys/net/sppp/if_spppsubr.c b/sys/net/sppp/if_spppsubr.c
--- a/sys/net/sppp/if_spppsubr.c
+++ b/sys/net/sppp/if_spppsubr.c
@@ -4387,7 +4387,7 @@
 			    SPP_ARGS(ifp));
 			name = 1 + (u_char *)(h + 1);
 			name_len = name[-1];
-			if (len > 5 && name_len < len+4) {
+			if (len > 5 && name_len < len-4) {
 				log(-1, ": ");
 				sppp_print_string(name, name_len);
 			}
@@ -4423,7 +4423,7 @@
 			    SPP_ARGS(ifp));
 			name = 1 + (u_char *)(h + 1);
 			name_len = name[-1];
-			if (len > 5 && name_len < len+4) {
+			if (len > 5 && name_len < len-4) {
 				log(-1, ": ");
 				sppp_print_string(name, name_len);
 			}