diff --git a/src/forward.c b/src/forward.c
index 71ca45c..dd22a45 100644
--- a/src/forward.c
+++ b/src/forward.c
@@ -65,13 +65,15 @@
 	  struct in_pktinfo p;
 	  p.ipi_ifindex = 0;
 	  p.ipi_spec_dst = source->addr4;
+	  msg.msg_controllen = CMSG_SPACE(sizeof(struct in_pktinfo));
 	  memcpy(CMSG_DATA(cmptr), &p, sizeof(p));
-	  msg.msg_controllen = cmptr->cmsg_len = CMSG_LEN(sizeof(struct in_pktinfo));
+	  cmptr->cmsg_len = CMSG_LEN(sizeof(struct in_pktinfo));
 	  cmptr->cmsg_level = IPPROTO_IP;
 	  cmptr->cmsg_type = IP_PKTINFO;
 #elif defined(IP_SENDSRCADDR)
+	  msg.msg_controllen = CMSG_SPACE(sizeof(struct in_addr));
 	  memcpy(CMSG_DATA(cmptr), &(source->addr4), sizeof(source->addr4));
-	  msg.msg_controllen = cmptr->cmsg_len = CMSG_LEN(sizeof(struct in_addr));
+	  cmptr->cmsg_len = CMSG_LEN(sizeof(struct in_addr));
 	  cmptr->cmsg_level = IPPROTO_IP;
 	  cmptr->cmsg_type = IP_SENDSRCADDR;
 #endif
@@ -81,8 +83,9 @@
 	  struct in6_pktinfo p;
 	  p.ipi6_ifindex = iface; /* Need iface for IPv6 to handle link-local addrs */
 	  p.ipi6_addr = source->addr6;
+	  msg.msg_controllen = CMSG_SPACE(sizeof(struct in6_pktinfo));
 	  memcpy(CMSG_DATA(cmptr), &p, sizeof(p));
-	  msg.msg_controllen = cmptr->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo));
+	  cmptr->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo));
 	  cmptr->cmsg_type = daemon->v6pktinfo;
 	  cmptr->cmsg_level = IPPROTO_IPV6;
 	}