diff --git a/pimd/pim_igmp.c b/pimd/pim_igmp.c
index a0a4aa8..dcb9a9b 100644
--- a/pimd/pim_igmp.c
+++ b/pimd/pim_igmp.c
@@ -679,7 +679,7 @@
   char to_str[100];
     
   if (len < sizeof(*ip_hdr)) {
-    zlog_warn("IGMP packet size=%d shorter than minimum=%d",
+    zlog_warn("IGMP packet size=%zu shorter than minimum=%zu",
 	      len, sizeof(*ip_hdr));
     return -1;
   }
@@ -692,7 +692,7 @@
   ip_hlen = ip_hdr->ip_hl << 2; /* ip_hl gives length in 4-byte words */
 
   if (PIM_DEBUG_IGMP_PACKETS) {
-    zlog_debug("Recv IP packet from %s to %s on %s: size=%d ip_header_size=%d ip_proto=%d",
+    zlog_debug("Recv IP packet from %s to %s on %s: size=%zu ip_header_size=%zu ip_proto=%d",
 	       from_str, to_str, igmp->interface->name, len, ip_hlen, ip_hdr->ip_p);
   }
 
@@ -703,12 +703,12 @@
   }
 
   if (ip_hlen < PIM_IP_HEADER_MIN_LEN) {
-    zlog_warn("IP packet header size=%d shorter than minimum=%d",
+    zlog_warn("IP packet header size=%zu shorter than minimum=%d",
 	      ip_hlen, PIM_IP_HEADER_MIN_LEN);
     return -1;
   }
   if (ip_hlen > PIM_IP_HEADER_MAX_LEN) {
-    zlog_warn("IP packet header size=%d greater than maximum=%d",
+    zlog_warn("IP packet header size=%zu greater than maximum=%d",
 	      ip_hlen, PIM_IP_HEADER_MAX_LEN);
     return -1;
   }