diff --git a/include/types/dns.h b/include/types/dns.h
index c7338c7..06e014c 100644
--- a/include/types/dns.h
+++ b/include/types/dns.h
@@ -82,7 +82,7 @@
 #define SRV_MAX_PREF_NET 5
 
 /* DNS header size */
-#define DNS_HEADER_SIZE		sizeof(struct dns_header)
+#define DNS_HEADER_SIZE		((int)sizeof(struct dns_header))
 
 /* DNS resolution pool size, per resolvers section */
 #define DNS_DEFAULT_RESOLUTION_POOL_SIZE	64