diff --git a/src/dns_conf.c b/src/dns_conf.c
index b9f6743..5422b61 100644
--- a/src/dns_conf.c
+++ b/src/dns_conf.c
@@ -122,7 +122,7 @@ char dns_conf_ca_path[DNS_MAX_PATH];
 
 char dns_conf_cache_file[DNS_MAX_PATH];
 int dns_conf_cache_persist = 2;
-int dns_conf_cache_checkpoint_time;
+int dns_conf_cache_checkpoint_time = DNS_DEFAULT_CHECKPOINT_TIME;
 
 /* auditing */
 int dns_conf_audit_enable = 0;
diff --git a/src/dns_conf.h b/src/dns_conf.h
index de77af0..d9cbe44 100644
--- a/src/dns_conf.h
+++ b/src/dns_conf.h
@@ -59,6 +59,7 @@ extern "C" {
 #define DNS_MAX_CONF_CNAME_LEN 256
 #define MAX_QTYPE_NUM 65535
 #define DNS_MAX_REPLY_IP_NUM 8
+#define DNS_DEFAULT_CHECKPOINT_TIME (3600 * 24)
 
 #define SMARTDNS_CONF_FILE "/etc/smartdns/smartdns.conf"
 #define SMARTDNS_LOG_FILE "/var/log/smartdns/smartdns.log"