diff --git a/bufferevent-internal.h b/bufferevent-internal.h
index 3b35b0cb..3ed73b30 100644
--- a/bufferevent-internal.h
+++ b/bufferevent-internal.h
@@ -23,8 +23,8 @@
  * (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 _BUFFEREVENT_INTERNAL_H_
-#define _BUFFEREVENT_INTERNAL_H_
+#ifndef BUFFEREVENT_INTERNAL_H_INCLUDED_
+#define BUFFEREVENT_INTERNAL_H_INCLUDED_
 
 #ifdef __cplusplus
 extern "C" {
@@ -418,4 +418,4 @@ int _bufferevent_ratelim_init(struct bufferevent_private *bev);
 #endif
 
 
-#endif /* _BUFFEREVENT_INTERNAL_H_ */
+#endif /* BUFFEREVENT_INTERNAL_H_INCLUDED_ */
diff --git a/changelist-internal.h b/changelist-internal.h
index 6ed432a2..72cd0fad 100644
--- a/changelist-internal.h
+++ b/changelist-internal.h
@@ -23,8 +23,8 @@
  * (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 _CHANGELIST_H_
-#define _CHANGELIST_H_
+#ifndef CHANGELIST_INTERNAL_H_INCLUDED_
+#define CHANGELIST_INTERNAL_H_INCLUDED_
 
 /*
   A "changelist" is a list of all the fd status changes that should be made
diff --git a/defer-internal.h b/defer-internal.h
index d8443925..5fe3a365 100644
--- a/defer-internal.h
+++ b/defer-internal.h
@@ -23,8 +23,8 @@
  * (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 _DEFER_INTERNAL_H_
-#define _DEFER_INTERNAL_H_
+#ifndef DEFER_INTERNAL_H_INCLUDED_
+#define DEFER_INTERNAL_H_INCLUDED_
 
 #ifdef __cplusplus
 extern "C" {
@@ -102,5 +102,5 @@ void event_deferred_cb_schedule(struct deferred_cb_queue *, struct deferred_cb *
 void event_deferred_cb_queue_init(struct deferred_cb_queue *);
 struct deferred_cb_queue *event_base_get_deferred_cb_queue(struct event_base *);
 
-#endif /* _EVENT_INTERNAL_H_ */
+#endif /* EVENT_INTERNAL_H_INCLUDED_ */
 
diff --git a/evbuffer-internal.h b/evbuffer-internal.h
index 426955df..71ee3bea 100644
--- a/evbuffer-internal.h
+++ b/evbuffer-internal.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 _EVBUFFER_INTERNAL_H_
-#define _EVBUFFER_INTERNAL_H_
+#ifndef EVBUFFER_INTERNAL_H_INCLUDED_
+#define EVBUFFER_INTERNAL_H_INCLUDED_
 
 #ifdef __cplusplus
 extern "C" {
@@ -326,4 +326,4 @@ void evbuffer_invoke_callbacks(struct evbuffer *buf);
 }
 #endif
 
-#endif /* _EVBUFFER_INTERNAL_H_ */
+#endif /* EVBUFFER_INTERNAL_H_INCLUDED_ */
diff --git a/event-internal.h b/event-internal.h
index ebd5002b..d66884da 100644
--- a/event-internal.h
+++ b/event-internal.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 _EVENT_INTERNAL_H_
-#define _EVENT_INTERNAL_H_
+#ifndef EVENT_INTERNAL_H_INCLUDED_
+#define EVENT_INTERNAL_H_INCLUDED_
 
 #ifdef __cplusplus
 extern "C" {
@@ -380,5 +380,5 @@ int event_base_foreach_event_(struct event_base *base,
 }
 #endif
 
-#endif /* _EVENT_INTERNAL_H_ */
+#endif /* EVENT_INTERNAL_H_INCLUDED_ */
 
diff --git a/evmap-internal.h b/evmap-internal.h
index 77f26129..9ff63c18 100644
--- a/evmap-internal.h
+++ b/evmap-internal.h
@@ -23,8 +23,8 @@
  * (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 _EVMAP_H_
-#define _EVMAP_H_
+#ifndef EVMAP_INTERNAL_H_INCLUDED_
+#define EVMAP_INTERNAL_H_INCLUDED_
 
 /** @file evmap-internal.h
  *
@@ -114,4 +114,4 @@ int evmap_foreach_event(struct event_base *base,
     event_base_foreach_event_cb fn,
     void *arg);
 
-#endif /* _EVMAP_H_ */
+#endif /* EVMAP_INTERNAL_H_INCLUDED_ */
diff --git a/evrpc-internal.h b/evrpc-internal.h
index d6ea41a7..b50eccfe 100644
--- a/evrpc-internal.h
+++ b/evrpc-internal.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 _EVRPC_INTERNAL_H_
-#define _EVRPC_INTERNAL_H_
+#ifndef EVRPC_INTERNAL_H_INCLUDED_
+#define EVRPC_INTERNAL_H_INCLUDED_
 
 #include "http-internal.h"
 
@@ -201,4 +201,4 @@ struct evrpc_request_wrapper {
 	int (*reply_unmarshal)(void *, struct evbuffer*);
 };
 
-#endif /* _EVRPC_INTERNAL_H_ */
+#endif /* EVRPC_INTERNAL_H_INCLUDED_ */
diff --git a/evsignal-internal.h b/evsignal-internal.h
index 45566144..7c27ec87 100644
--- a/evsignal-internal.h
+++ b/evsignal-internal.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 _EVSIGNAL_H_
-#define _EVSIGNAL_H_
+#ifndef EVSIGNAL_INTERNAL_H_INCLUDED_
+#define EVSIGNAL_INTERNAL_H_INCLUDED_
 
 #ifndef evutil_socket_t
 #include "event2/util.h"
@@ -61,4 +61,4 @@ void evsig_dealloc(struct event_base *);
 
 void evsig_set_base(struct event_base *base);
 
-#endif /* _EVSIGNAL_H_ */
+#endif /* EVSIGNAL_INTERNAL_H_INCLUDED_ */
diff --git a/evthread-internal.h b/evthread-internal.h
index 0a139d4b..152c6b9b 100644
--- a/evthread-internal.h
+++ b/evthread-internal.h
@@ -23,8 +23,8 @@
  * (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 _EVTHREAD_INTERNAL_H_
-#define _EVTHREAD_INTERNAL_H_
+#ifndef EVTHREAD_INTERNAL_H_INCLUDED_
+#define EVTHREAD_INTERNAL_H_INCLUDED_
 
 #ifdef __cplusplus
 extern "C" {
@@ -381,4 +381,4 @@ int evutil_secure_rng_global_setup_locks_(const int enable_locks);
 }
 #endif
 
-#endif /* _EVTHREAD_INTERNAL_H_ */
+#endif /* EVTHREAD_INTERNAL_H_INCLUDED_ */
diff --git a/ht-internal.h b/ht-internal.h
index 1c1c134f..1d3b0890 100644
--- a/ht-internal.h
+++ b/ht-internal.h
@@ -5,8 +5,8 @@
 
 /* Based on ideas by Christopher Clark and interfaces from Niels Provos. */
 
-#ifndef _EVENT_HT_H
-#define _EVENT_HT_H
+#ifndef HT_INTERNAL_H_INCLUDED_
+#define HT_INTERNAL_H_INCLUDED_
 
 #define HT_HEAD(name, type)                                             \
   struct name {                                                         \
diff --git a/http-internal.h b/http-internal.h
index 6910b350..b1056f41 100644
--- a/http-internal.h
+++ b/http-internal.h
@@ -7,8 +7,8 @@
  * need to know about these.
  */
 
-#ifndef _HTTP_INTERNAL_H_
-#define _HTTP_INTERNAL_H_
+#ifndef HTTP_INTERNAL_H_INCLUDED_
+#define HTTP_INTERNAL_H_INCLUDED_
 
 #include "event2/event_struct.h"
 #include "util-internal.h"
diff --git a/include/evdns.h b/include/evdns.h
index 513f9b70..8672db03 100644
--- a/include/evdns.h
+++ b/include/evdns.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 _EVDNS_H_
-#define _EVDNS_H_
+#ifndef EVENT1_EVDNS_H_INCLUDED_
+#define EVENT1_EVDNS_H_INCLUDED_
 
 /** @file evdns.h
 
@@ -42,4 +42,4 @@
 #include <event2/dns_compat.h>
 #include <event2/dns_struct.h>
 
-#endif /* _EVDNS_H_ */
+#endif /* EVENT1_EVDNS_H_INCLUDED_ */
diff --git a/include/event.h b/include/event.h
index e0634201..3a1b0c2c 100644
--- a/include/event.h
+++ b/include/event.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 _EVENT_H_
-#define _EVENT_H_
+#ifndef EVENT1_EVENT_H_INCLUDED_
+#define EVENT1_EVENT_H_INCLUDED_
 
 /** @file event.h
 
@@ -82,4 +82,4 @@ typedef unsigned short u_short;
 }
 #endif
 
-#endif /* _EVENT_H_ */
+#endif /* EVENT1_EVENT_H_INCLUDED_ */
diff --git a/include/event2/buffer.h b/include/event2/buffer.h
index 2e3b0f46..0e7919c4 100644
--- a/include/event2/buffer.h
+++ b/include/event2/buffer.h
@@ -23,8 +23,8 @@
  * (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_BUFFER_H_
-#define _EVENT2_BUFFER_H_
+#ifndef EVENT2_BUFFER_H_INCLUDED_
+#define EVENT2_BUFFER_H_INCLUDED_
 
 /** @file event2/buffer.h
 
@@ -1003,4 +1003,4 @@ size_t evbuffer_add_iovec(struct evbuffer * buffer, struct evbuffer_iovec * vec,
 }
 #endif
 
-#endif /* _EVENT2_BUFFER_H_ */
+#endif /* EVENT2_BUFFER_H_INCLUDED_ */
diff --git a/include/event2/buffer_compat.h b/include/event2/buffer_compat.h
index a713ee32..c155332e 100644
--- a/include/event2/buffer_compat.h
+++ b/include/event2/buffer_compat.h
@@ -24,8 +24,8 @@
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#ifndef _EVENT2_BUFFER_COMPAT_H_
-#define _EVENT2_BUFFER_COMPAT_H_
+#ifndef EVENT2_BUFFER_COMPAT_H_INCLUDED_
+#define EVENT2_BUFFER_COMPAT_H_INCLUDED_
 
 /** @file event2/buffer_compat.h
 
diff --git a/include/event2/bufferevent.h b/include/event2/bufferevent.h
index a7d360d5..85cdf71a 100644
--- a/include/event2/bufferevent.h
+++ b/include/event2/bufferevent.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_BUFFEREVENT_H_
-#define _EVENT2_BUFFEREVENT_H_
+#ifndef EVENT2_BUFFEREVENT_H_INCLUDED_
+#define EVENT2_BUFFEREVENT_H_INCLUDED_
 
 /**
    @file event2/bufferevent.h
@@ -862,4 +862,4 @@ bufferevent_rate_limit_group_reset_totals(
 }
 #endif
 
-#endif /* _EVENT2_BUFFEREVENT_H_ */
+#endif /* EVENT2_BUFFEREVENT_H_INCLUDED_ */
diff --git a/include/event2/bufferevent_compat.h b/include/event2/bufferevent_compat.h
index 3256fd16..65482042 100644
--- a/include/event2/bufferevent_compat.h
+++ b/include/event2/bufferevent_compat.h
@@ -25,8 +25,8 @@
  * (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_BUFFEREVENT_COMPAT_H_
-#define _EVENT2_BUFFEREVENT_COMPAT_H_
+#ifndef EVENT2_BUFFEREVENT_COMPAT_H_INCLUDED_
+#define EVENT2_BUFFEREVENT_COMPAT_H_INCLUDED_
 
 #define evbuffercb bufferevent_data_cb
 #define everrorcb bufferevent_event_cb
diff --git a/include/event2/bufferevent_ssl.h b/include/event2/bufferevent_ssl.h
index f32a035f..b0bd82fc 100644
--- a/include/event2/bufferevent_ssl.h
+++ b/include/event2/bufferevent_ssl.h
@@ -23,8 +23,8 @@
  * (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_BUFFEREVENT_SSL_H_
-#define _EVENT2_BUFFEREVENT_SSL_H_
+#ifndef EVENT2_BUFFEREVENT_SSL_H_INCLUDED_
+#define EVENT2_BUFFEREVENT_SSL_H_INCLUDED_
 
 /** @file event2/bufferevent_ssl.h
 
@@ -124,4 +124,4 @@ unsigned long bufferevent_get_openssl_error(struct bufferevent *bev);
 }
 #endif
 
-#endif /* _EVENT2_BUFFEREVENT_SSL_H_ */
+#endif /* EVENT2_BUFFEREVENT_SSL_H_INCLUDED_ */
diff --git a/include/event2/bufferevent_struct.h b/include/event2/bufferevent_struct.h
index cfac3127..e84c082c 100644
--- a/include/event2/bufferevent_struct.h
+++ b/include/event2/bufferevent_struct.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_BUFFEREVENT_STRUCT_H_
-#define _EVENT2_BUFFEREVENT_STRUCT_H_
+#ifndef EVENT2_BUFFEREVENT_STRUCT_H_INCLUDED_
+#define EVENT2_BUFFEREVENT_STRUCT_H_INCLUDED_
 
 /** @file event2/bufferevent_struct.h
 
@@ -113,4 +113,4 @@ struct bufferevent {
 }
 #endif
 
-#endif /* _EVENT2_BUFFEREVENT_STRUCT_H_ */
+#endif /* EVENT2_BUFFEREVENT_STRUCT_H_INCLUDED_ */
diff --git a/include/event2/dns.h b/include/event2/dns.h
index ad7227f5..4b03d760 100644
--- a/include/event2/dns.h
+++ b/include/event2/dns.h
@@ -132,8 +132,8 @@
  * with the next probe.
  */
 
-#ifndef _EVENT2_DNS_H_
-#define _EVENT2_DNS_H_
+#ifndef EVENT2_DNS_H_INCLUDED_
+#define EVENT2_DNS_H_INCLUDED_
 
 #ifdef __cplusplus
 extern "C" {
@@ -640,4 +640,4 @@ void evdns_getaddrinfo_cancel(struct evdns_getaddrinfo_request *req);
 }
 #endif
 
-#endif  /* !_EVENT2_DNS_H_ */
+#endif  /* !EVENT2_DNS_H_INCLUDED_ */
diff --git a/include/event2/dns_compat.h b/include/event2/dns_compat.h
index 1469a014..965fd654 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
 
@@ -333,4 +333,4 @@ int evdns_config_windows_nameservers(void);
 }
 #endif
 
-#endif /* _EVENT2_EVENT_COMPAT_H_ */
+#endif /* EVENT2_EVENT_COMPAT_H_INCLUDED_ */
diff --git a/include/event2/dns_struct.h b/include/event2/dns_struct.h
index 620c66ec..593a8a70 100644
--- a/include/event2/dns_struct.h
+++ b/include/event2/dns_struct.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_STRUCT_H_
-#define _EVENT2_DNS_STRUCT_H_
+#ifndef EVENT2_DNS_STRUCT_H_INCLUDED_
+#define EVENT2_DNS_STRUCT_H_INCLUDED_
 
 /** @file event2/dns_struct.h
 
@@ -76,5 +76,5 @@ struct evdns_server_question {
 }
 #endif
 
-#endif /* _EVENT2_DNS_STRUCT_H_ */
+#endif /* EVENT2_DNS_STRUCT_H_INCLUDED_ */
 
diff --git a/include/event2/event.h b/include/event2/event.h
index 8ab34da1..b75261be 100644
--- a/include/event2/event.h
+++ b/include/event2/event.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_EVENT_H_
-#define _EVENT2_EVENT_H_
+#ifndef EVENT2_EVENT_H_INCLUDED_
+#define EVENT2_EVENT_H_INCLUDED_
 
 /**
    @mainpage
@@ -1283,4 +1283,4 @@ int event_base_update_cache_time(struct event_base *base);
 }
 #endif
 
-#endif /* _EVENT2_EVENT_H_ */
+#endif /* EVENT2_EVENT_H_INCLUDED_ */
diff --git a/include/event2/event_compat.h b/include/event2/event_compat.h
index a1d2f252..87403a4d 100644
--- a/include/event2/event_compat.h
+++ b/include/event2/event_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_EVENT_COMPAT_H_
-#define _EVENT2_EVENT_COMPAT_H_
+#ifndef EVENT2_EVENT_COMPAT_H_INCLUDED_
+#define EVENT2_EVENT_COMPAT_H_INCLUDED_
 
 /** @file event2/event_compat.h
 
@@ -217,4 +217,4 @@ void event_set(struct event *, evutil_socket_t, short, void (*)(evutil_socket_t,
 }
 #endif
 
-#endif /* _EVENT2_EVENT_COMPAT_H_ */
+#endif /* EVENT2_EVENT_COMPAT_H_INCLUDED_ */
diff --git a/include/event2/event_struct.h b/include/event2/event_struct.h
index 714a6cd0..ee1b2566 100644
--- a/include/event2/event_struct.h
+++ b/include/event2/event_struct.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_EVENT_STRUCT_H_
-#define _EVENT2_EVENT_STRUCT_H_
+#ifndef EVENT2_EVENT_STRUCT_H_INCLUDED_
+#define EVENT2_EVENT_STRUCT_H_INCLUDED_
 
 /** @file event2/event_struct.h
 
@@ -156,4 +156,4 @@ LIST_HEAD (event_dlist, event);
 }
 #endif
 
-#endif /* _EVENT2_EVENT_STRUCT_H_ */
+#endif /* EVENT2_EVENT_STRUCT_H_INCLUDED_ */
diff --git a/include/event2/http.h b/include/event2/http.h
index 144661b3..109b73b0 100644
--- a/include/event2/http.h
+++ b/include/event2/http.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_HTTP_H_
-#define _EVENT2_HTTP_H_
+#ifndef EVENT2_HTTP_H_INCLUDED_
+#define EVENT2_HTTP_H_INCLUDED_
 
 /* For int types. */
 #include <event2/util.h>
@@ -927,4 +927,4 @@ char *evhttp_uri_join(struct evhttp_uri *uri, char *buf, size_t limit);
 }
 #endif
 
-#endif /* _EVENT2_HTTP_H_ */
+#endif /* EVENT2_HTTP_H_INCLUDED_ */
diff --git a/include/event2/http_compat.h b/include/event2/http_compat.h
index c29c48e9..0d9af17f 100644
--- a/include/event2/http_compat.h
+++ b/include/event2/http_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_HTTP_COMPAT_H_
-#define _EVENT2_HTTP_COMPAT_H_
+#ifndef EVENT2_HTTP_COMPAT_H_INCLUDED_
+#define EVENT2_HTTP_COMPAT_H_INCLUDED_
 
 /** @file event2/http_compat.h
 
@@ -87,4 +87,4 @@ void evhttp_connection_set_base(struct evhttp_connection *evcon,
 }
 #endif
 
-#endif /* _EVENT2_EVENT_COMPAT_H_ */
+#endif /* EVENT2_EVENT_COMPAT_H_INCLUDED_ */
diff --git a/include/event2/http_struct.h b/include/event2/http_struct.h
index 75f7d9dd..f245dff8 100644
--- a/include/event2/http_struct.h
+++ b/include/event2/http_struct.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_HTTP_STRUCT_H_
-#define _EVENT2_HTTP_STRUCT_H_
+#ifndef EVENT2_HTTP_STRUCT_H_INCLUDED_
+#define EVENT2_HTTP_STRUCT_H_INCLUDED_
 
 /** @file event2/http_struct.h
 
@@ -126,5 +126,5 @@ struct {
 }
 #endif
 
-#endif /* _EVENT2_HTTP_STRUCT_H_ */
+#endif /* EVENT2_HTTP_STRUCT_H_INCLUDED_ */
 
diff --git a/include/event2/keyvalq_struct.h b/include/event2/keyvalq_struct.h
index ab8040bf..c028c0b2 100644
--- a/include/event2/keyvalq_struct.h
+++ b/include/event2/keyvalq_struct.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_EVENT_KEYVALQ_STRUCT_H_
-#define _EVENT2_EVENT_KEYVALQ_STRUCT_H_
+#ifndef EVENT2_KEYVALQ_STRUCT_H_INCLUDED_
+#define EVENT2_KEYVALQ_STRUCT_H_INCLUDED_
 
 #ifdef __cplusplus
 extern "C" {
diff --git a/include/event2/listener.h b/include/event2/listener.h
index 10887bae..7bdf9bfc 100644
--- a/include/event2/listener.h
+++ b/include/event2/listener.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_LISTENER_H_
-#define _EVENT2_LISTENER_H_
+#ifndef EVENT2_LISTENER_H_INCLUDED_
+#define EVENT2_LISTENER_H_INCLUDED_
 
 #ifdef __cplusplus
 extern "C" {
diff --git a/include/event2/rpc.h b/include/event2/rpc.h
index 2ac7ad2b..a780ff89 100644
--- a/include/event2/rpc.h
+++ b/include/event2/rpc.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_RPC_H_
-#define _EVENT2_RPC_H_
+#ifndef EVENT2_RPC_H_INCLUDED_
+#define EVENT2_RPC_H_INCLUDED_
 
 #ifdef __cplusplus
 extern "C" {
@@ -76,7 +76,7 @@ extern "C" {
 #define EVTAG_HAS(msg, member) \
 	((msg)->member##_set == 1)
 
-#ifndef _EVENT2_RPC_COMPAT_H_
+#ifndef EVENT2_RPC_COMPAT_H_INCLUDED_
 
 /**
    Assigns a value to the member in the message.
@@ -119,7 +119,7 @@ extern "C" {
 #define EVTAG_GET_WITH_LEN(msg, member, pvalue, plen)	\
 	(*(msg)->base->member##_get)((msg), (pvalue), (plen))
 
-#endif  /* _EVENT2_RPC_COMPAT_H_ */
+#endif  /* EVENT2_RPC_COMPAT_H_INCLUDED_ */
 
 /**
    Adds a value to an array.
@@ -593,4 +593,4 @@ void evrpc_request_set_cb(struct evrpc_request_wrapper *ctx,
 }
 #endif
 
-#endif /* _EVENT2_RPC_H_ */
+#endif /* EVENT2_RPC_H_INCLUDED_ */
diff --git a/include/event2/rpc_compat.h b/include/event2/rpc_compat.h
index a4e24bb6..8d8334d2 100644
--- a/include/event2/rpc_compat.h
+++ b/include/event2/rpc_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_RPC_COMPAT_H_
-#define _EVENT2_RPC_COMPAT_H_
+#ifndef EVENT2_RPC_COMPAT_H_INCLUDED_
+#define EVENT2_RPC_COMPAT_H_INCLUDED_
 
 /** @file event2/rpc_compat.h
 
@@ -58,4 +58,4 @@ extern "C" {
 }
 #endif
 
-#endif /* _EVENT2_EVENT_COMPAT_H_ */
+#endif /* EVENT2_EVENT_COMPAT_H_INCLUDED_ */
diff --git a/include/event2/rpc_struct.h b/include/event2/rpc_struct.h
index c339ae58..8f691f49 100644
--- a/include/event2/rpc_struct.h
+++ b/include/event2/rpc_struct.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_RPC_STRUCT_H_
-#define _EVENT2_RPC_STRUCT_H_
+#ifndef EVENT2_RPC_STRUCT_H_INCLUDED_
+#define EVENT2_RPC_STRUCT_H_INCLUDED_
 
 #ifdef __cplusplus
 extern "C" {
@@ -97,4 +97,4 @@ struct evrpc {
 }
 #endif
 
-#endif /* _EVENT2_RPC_STRUCT_H_ */
+#endif /* EVENT2_RPC_STRUCT_H_INCLUDED_ */
diff --git a/include/event2/tag.h b/include/event2/tag.h
index 36a85bba..7632bd58 100644
--- a/include/event2/tag.h
+++ b/include/event2/tag.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_TAG_H_
-#define _EVENT2_TAG_H_
+#ifndef EVENT2_TAG_H_INCLUDED_
+#define EVENT2_TAG_H_INCLUDED_
 
 /** @file event2/tag.h
 
@@ -121,4 +121,4 @@ int evtag_unmarshal_timeval(struct evbuffer *evbuf, ev_uint32_t need_tag,
 }
 #endif
 
-#endif /* _EVENT2_TAG_H_ */
+#endif /* EVENT2_TAG_H_INCLUDED_ */
diff --git a/include/event2/tag_compat.h b/include/event2/tag_compat.h
index 73c19330..a276c0d3 100644
--- a/include/event2/tag_compat.h
+++ b/include/event2/tag_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_TAG_COMPAT_H_
-#define _EVENT2_TAG_COMPAT_H_
+#ifndef EVENT2_TAG_COMPAT_H_INCLUDED_
+#define EVENT2_TAG_COMPAT_H_INCLUDED_
 
 /** @file event2/tag_compat.h
 
@@ -46,4 +46,4 @@
 #define encode_int64(evbuf, number) evtag_encode_int64((evbuf), (number))
 /**@}*/
 
-#endif /* _EVENT2_TAG_H_ */
+#endif /* EVENT2_TAG_H_INCLUDED_ */
diff --git a/include/event2/thread.h b/include/event2/thread.h
index e17ac025..43b58d08 100644
--- a/include/event2/thread.h
+++ b/include/event2/thread.h
@@ -23,8 +23,8 @@
  * (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_THREAD_H_
-#define _EVENT2_THREAD_H_
+#ifndef EVENT2_THREAD_H_INCLUDED_
+#define EVENT2_THREAD_H_INCLUDED_
 
 /** @file event2/thread.h
 
@@ -233,4 +233,4 @@ int evthread_make_base_notifiable(struct event_base *base);
 }
 #endif
 
-#endif /* _EVENT2_THREAD_H_ */
+#endif /* EVENT2_THREAD_H_INCLUDED_ */
diff --git a/include/event2/util.h b/include/event2/util.h
index ad0398c6..72a8530b 100644
--- a/include/event2/util.h
+++ b/include/event2/util.h
@@ -23,8 +23,8 @@
  * (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_UTIL_H_
-#define _EVENT2_UTIL_H_
+#ifndef EVENT2_UTIL_H_INCLUDED_
+#define EVENT2_UTIL_H_INCLUDED_
 
 /** @file event2/util.h
 
@@ -713,4 +713,4 @@ void evutil_secure_rng_add_bytes(const char *dat, size_t datlen);
 }
 #endif
 
-#endif /* _EVUTIL_H_ */
+#endif /* EVENT1_EVUTIL_H_INCLUDED_ */
diff --git a/include/evhttp.h b/include/evhttp.h
index 5ce15e65..549bc9b1 100644
--- a/include/evhttp.h
+++ b/include/evhttp.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 _EVHTTP_H_
-#define _EVHTTP_H_
+#ifndef EVENT1_EVHTTP_H_INCLUDED_
+#define EVENT1_EVHTTP_H_INCLUDED_
 
 /** @file evhttp.h
 
@@ -42,4 +42,4 @@
 #include <event2/http_struct.h>
 #include <event2/http_compat.h>
 
-#endif /* _EVHTTP_H_ */
+#endif /* EVENT1_EVHTTP_H_INCLUDED_ */
diff --git a/include/evrpc.h b/include/evrpc.h
index 5b88262d..7e986f7d 100644
--- a/include/evrpc.h
+++ b/include/evrpc.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 _EVRPC_H_
-#define _EVRPC_H_
+#ifndef EVENT1_EVRPC_H_INCLUDED_
+#define EVENT1_EVRPC_H_INCLUDED_
 
 /** @file evrpc.h
 
@@ -42,4 +42,4 @@
 #include <event2/rpc_struct.h>
 #include <event2/rpc_compat.h>
 
-#endif /* _EVRPC_H_ */
+#endif /* EVENT1_EVRPC_H_INCLUDED_ */
diff --git a/include/evutil.h b/include/evutil.h
index 02bca89e..12c137d7 100644
--- a/include/evutil.h
+++ b/include/evutil.h
@@ -23,8 +23,8 @@
  * (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 _EVUTIL_H_
-#define _EVUTIL_H_
+#ifndef EVENT1_EVUTIL_H_INCLUDED_
+#define EVENT1_EVUTIL_H_INCLUDED_
 
 /** @file evutil.h
 
@@ -36,4 +36,4 @@
 
 #include <event2/util.h>
 
-#endif /* _EVUTIL_H_ */
+#endif /* EVENT1_EVUTIL_H_INCLUDED_ */
diff --git a/iocp-internal.h b/iocp-internal.h
index 22321e45..6eaf96c2 100644
--- a/iocp-internal.h
+++ b/iocp-internal.h
@@ -24,8 +24,8 @@
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#ifndef _EVENT_IOCP_INTERNAL_H
-#define _EVENT_IOCP_INTERNAL_H
+#ifndef IOCP_INTERNAL_H_INCLUDED_
+#define IOCP_INTERNAL_H_INCLUDED_
 
 #ifdef __cplusplus
 extern "C" {
diff --git a/ipv6-internal.h b/ipv6-internal.h
index 7444b0ff..0c207377 100644
--- a/ipv6-internal.h
+++ b/ipv6-internal.h
@@ -27,8 +27,8 @@
 /* Internal use only: Fake IPv6 structures and values on platforms that
  * do not have them */
 
-#ifndef _EVENT_IPV6_INTERNAL_H
-#define _EVENT_IPV6_INTERNAL_H
+#ifndef IPV6_INTERNAL_H_INCLUDED_
+#define IPV6_INTERNAL_H_INCLUDED_
 
 #include "event2/event-config.h"
 #include "evconfig-private.h"
diff --git a/log-internal.h b/log-internal.h
index 47064e22..fb24af1a 100644
--- a/log-internal.h
+++ b/log-internal.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 _LOG_H_
-#define _LOG_H_
+#ifndef LOG_INTERNAL_H_INCLUDED_
+#define LOG_INTERNAL_H_INCLUDED_
 
 #include "event2/util.h"
 
diff --git a/minheap-internal.h b/minheap-internal.h
index 2f2a8dc6..466530ab 100644
--- a/minheap-internal.h
+++ b/minheap-internal.h
@@ -25,8 +25,8 @@
  * (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 _MIN_HEAP_H_
-#define _MIN_HEAP_H_
+#ifndef MINHEAP_INTERNAL_H_INCLUDED_
+#define MINHEAP_INTERNAL_H_INCLUDED_
 
 #include "event2/event-config.h"
 #include "evconfig-private.h"
@@ -186,4 +186,4 @@ void min_heap_shift_down_(min_heap_t* s, unsigned hole_index, struct event* e)
     (s->p[hole_index] = e)->ev_timeout_pos.min_heap_idx = hole_index;
 }
 
-#endif /* _MIN_HEAP_H_ */
+#endif /* MINHEAP_INTERNAL_H_INCLUDED_ */
diff --git a/mm-internal.h b/mm-internal.h
index ff6d4758..4ba6fce4 100644
--- a/mm-internal.h
+++ b/mm-internal.h
@@ -23,8 +23,8 @@
  * (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 _EVENT_MM_INTERNAL_H
-#define _EVENT_MM_INTERNAL_H
+#ifndef MM_INTERNAL_H_INCLUDED_
+#define MM_INTERNAL_H_INCLUDED_
 
 #include <sys/types.h>
 
diff --git a/ratelim-internal.h b/ratelim-internal.h
index 4e3f8c4c..6c76e727 100644
--- a/ratelim-internal.h
+++ b/ratelim-internal.h
@@ -23,8 +23,8 @@
  * (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 _RATELIM_INTERNAL_H_
-#define _RATELIM_INTERNAL_H_
+#ifndef RATELIM_INTERNAL_H_INCLUDED_
+#define RATELIM_INTERNAL_H_INCLUDED_
 
 #ifdef __cplusplus
 extern "C" {
diff --git a/strlcpy-internal.h b/strlcpy-internal.h
index 5fb2fff1..2b74404b 100644
--- a/strlcpy-internal.h
+++ b/strlcpy-internal.h
@@ -1,5 +1,5 @@
-#ifndef _STRLCPY_INTERNAL_H_
-#define _STRLCPY_INTERNAL_H_
+#ifndef STRLCPY_INTERNAL_H_INCLUDED_
+#define STRLCPY_INTERNAL_H_INCLUDED_
 
 #ifdef __cplusplus
 extern "C" {
diff --git a/test/regress.h b/test/regress.h
index dd6e3fad..842d621a 100644
--- a/test/regress.h
+++ b/test/regress.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 _REGRESS_H_
-#define _REGRESS_H_
+#ifndef REGRESS_H_INCLUDED_
+#define REGRESS_H_INCLUDED_
 
 #ifdef __cplusplus
 extern "C" {
@@ -122,4 +122,4 @@ long timeval_msec_diff(const struct timeval *start, const struct timeval *end);
 }
 #endif
 
-#endif /* _REGRESS_H_ */
+#endif /* REGRESS_H_INCLUDED_ */
diff --git a/test/regress_testutils.h b/test/regress_testutils.h
index 1f09427d..f90b9c99 100644
--- a/test/regress_testutils.h
+++ b/test/regress_testutils.h
@@ -24,8 +24,8 @@
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#ifndef _TESTUTILS_H
-#define _TESTUTILS_H
+#ifndef REGRESS_TESTUTILS_H_INCLUDED_
+#define REGRESS_TESTUTILS_H_INCLUDED_
 
 #include "event2/dns.h"
 
@@ -62,5 +62,5 @@ struct sockaddr;
 int regress_get_listener_addr(struct evconnlistener *lev,
     struct sockaddr *sa, ev_socklen_t *socklen);
 
-#endif /* _TESTUTILS_H */
+#endif /* REGRESS_TESTUTILS_H_INCLUDED_ */
 
diff --git a/util-internal.h b/util-internal.h
index 52de23dd..2444dced 100644
--- a/util-internal.h
+++ b/util-internal.h
@@ -23,8 +23,8 @@
  * (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 _EVENT_UTIL_INTERNAL_H
-#define _EVENT_UTIL_INTERNAL_H
+#ifndef UTIL_INTERNAL_H_INCLUDED_
+#define UTIL_INTERNAL_H_INCLUDED_
 
 #include "event2/event-config.h"
 #include "evconfig-private.h"