Index: src/common/XAuth.cpp
--- src/common/XAuth.cpp.orig
+++ src/common/XAuth.cpp
@@ -33,6 +33,8 @@
 
 #ifdef __FreeBSD__
 #define HOST_NAME_MAX _POSIX_HOST_NAME_MAX
+#elif __OpenBSD__
+#include <limits.h>
 #endif
 
 #include "Configuration.h"
