diff --git a/mercurial/bdiff.c b/mercurial/bdiff.c
--- a/mercurial/bdiff.c
+++ b/mercurial/bdiff.c
@@ -34,7 +34,7 @@ static uint32_t htonl(uint32_t x)
 }
 #else
 #include <sys/types.h>
-#ifdef __BEOS__
+#if defined __BEOS__ && !defined __HAIKU__
 #include <ByteOrder.h>
 #else
 #include <arpa/inet.h>
diff --git a/mercurial/mpatch.c b/mercurial/mpatch.c
--- a/mercurial/mpatch.c
+++ b/mercurial/mpatch.c
@@ -52,7 +52,7 @@ static uint32_t ntohl(uint32_t x)
 #else
 /* not windows */
 # include <sys/types.h>
-# ifdef __BEOS__
+# if defined __BEOS__ && !defined __HAIKU__
 #  include <ByteOrder.h>
 # else
 #  include <arpa/inet.h>