diff --git a/netgraph/netgraph/ng_parse.c b/netgraph/netgraph/ng_parse.c
--- a/netgraph/netgraph/ng_parse.c
+++ b/netgraph/netgraph/ng_parse.c
@@ -1599,7 +1599,7 @@
 			case '0': case '1': case '2': case '3':
 			case '4': case '5': case '6': case '7':
 				for (x = k = 0;
-				    k < 3 && *v >= '0' && *v <= '7'; v++) {
+				    k < 3 && *v >= '0' && *v <= '7'; v++, k++) {
 					x = (x << 3) + (*v - '0');
 					off++;
 				}