diff --git a/src/nwfilter/nwfilter_dhcpsnoop.c b/src/nwfilter/nwfilter_dhcpsnoop.c
index 7cb0ac0773..ab9bf09fcd 100644
--- a/src/nwfilter/nwfilter_dhcpsnoop.c
+++ b/src/nwfilter/nwfilter_dhcpsnoop.c
@@ -250,7 +250,11 @@ struct _virNWFilterDHCPDecodeJob {
 # define DHCP_PKT_BURST         50 /* pkts/sec */
 # define DHCP_BURST_INTERVAL_S  10 /* sec */
 
-# define PCAP_BUFFERSIZE        (DHCP_PKT_BURST * PCAP_PBUFSIZE / 2)
+/*
+ * libpcap 1.5 requires a 128kb buffer
+ * 128 kb is bigger than (DHCP_PKT_BURST * PCAP_PBUFSIZE / 2)
+ */
+# define PCAP_BUFFERSIZE        (128 * 1024)
 
 # define MAX_QUEUED_JOBS        (DHCP_PKT_BURST + 2 * DHCP_PKT_RATE)