diff --git a/sys/netinet/ip_output.c b/sys/netinet/ip_output.c
index f1f0acdcf220..98da087285e8 100644
--- a/sys/netinet/ip_output.c
+++ b/sys/netinet/ip_output.c
@@ -1735,7 +1735,7 @@ ip_pcbopts(optname, pcbopt, m)
 			 */
 			bcopy((&cp[IPOPT_OFFSET+1] + sizeof(struct in_addr)),
 			    &cp[IPOPT_OFFSET+1],
-			    (unsigned)cnt + sizeof(struct in_addr));
+			    (unsigned)cnt - (IPOPT_MINOFF - 1));
 			break;
 		}
 	}