diff --git a/include/event2/dns_compat.h b/include/event2/dns_compat.h
index 7c1c776..965fd65 100644
--- a/include/event2/dns_compat.h
+++ b/include/event2/dns_compat.h
@@ -24,8 +24,8 @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
-#ifndef _EVENT2_DNS_COMPAT_H_
-#define _EVENT2_DNS_COMPAT_H_
+#ifndef EVENT2_DNS_COMPAT_H_INCLUDED_
+#define EVENT2_DNS_COMPAT_H_INCLUDED_
 
 /** @file event2/dns_compat.h
 
@@ -40,10 +40,10 @@
 #endif
 
 #include <event2/event-config.h>
-#ifdef _EVENT_HAVE_SYS_TYPES_H
+#ifdef EVENT__HAVE_SYS_TYPES_H
 #include <sys/types.h>
 #endif
-#ifdef _EVENT_HAVE_SYS_TIME_H
+#ifdef EVENT__HAVE_SYS_TIME_H
 #include <sys/time.h>
 #endif
 
@@ -324,7 +324,7 @@
 */
 struct evdns_server_port *evdns_add_server_port(evutil_socket_t socket, int flags, evdns_request_callback_fn_type callback, void *user_data);
 
-#ifdef WIN32
+#ifdef _WIN32
 int evdns_config_windows_nameservers(void);
 #define EVDNS_CONFIG_WINDOWS_NAMESERVERS_IMPLEMENTED
 #endif
@@ -333,4 +333,4 @@
 }
 #endif
 
-#endif /* _EVENT2_EVENT_COMPAT_H_ */
+#endif /* EVENT2_EVENT_COMPAT_H_INCLUDED_ */