diff --git a/public/build.h b/public/build.h
index 9cb7e25b..a087c22c 100644
--- a/public/build.h
+++ b/public/build.h
@@ -52,7 +52,7 @@ For more information, please refer to <http://unlicense.org/>
 #undef XASH_ARMv5
 #undef XASH_ARMv6
 #undef XASH_ARMv7
-#undef XASH_BIG_ENDIAN
+//#undef XASH_BIG_ENDIAN
 #undef XASH_BSD
 #undef XASH_E2K
 #undef XASH_EMSCRIPTEN
@@ -60,7 +60,7 @@ For more information, please refer to <http://unlicense.org/>
 #undef XASH_IOS
 #undef XASH_JS
 #undef XASH_LINUX
-#undef XASH_LITTLE_ENDIAN
+//#undef XASH_LITTLE_ENDIAN
 #undef XASH_MINGW
 #undef XASH_MIPS
 #undef XASH_MOBILE_PLATFORM
@@ -92,12 +92,14 @@ For more information, please refer to <http://unlicense.org/>
 	#if defined(__ANDROID__)
 		#define XASH_ANDROID 1
 	#endif // defined(__ANDROID__)
+	#define XASH_POSIX 1
 #elif defined(__APPLE__)
 	#include <TargetConditionals.h>
 	#define XASH_APPLE 1
 	#if TARGET_OS_IOS
 		#define XASH_IOS 1
 	#endif // TARGET_OS_IOS
+	#define XASH_POSIX 1
 #elif defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__)
 	#define XASH_BSD 1
 	#if defined(__FreeBSD__)
@@ -107,8 +109,12 @@ For more information, please refer to <http://unlicense.org/>
 	#elif defined(__OpenBSD__)
 		#define XASH_OPENBSD 1
 	#endif
+	#define XASH_POSIX 1
 #elif defined __EMSCRIPTEN__
 	#define XASH_EMSCRIPTEN 1
+#elif defined __WATCOMC__ && defined __DOS__
+	#define XASH_DOS4GW 1
+	#define XASH_LITTLE_ENDIAN
 #else
 #error "Place your operating system name here! If this is a mistake, try to fix conditions above and report a bug"
 #endif
@@ -127,7 +133,7 @@ For more information, please refer to <http://unlicense.org/>
 	#error "Both XASH_LITTLE_ENDIAN and XASH_BIG_ENDIAN are defined"
 #endif
 
-#if !defined(XASH_LITTLE_ENDIAN) || !defined(XASH_BIG_ENDIAN)
+#if !defined(XASH_LITTLE_ENDIAN) && !defined(XASH_BIG_ENDIAN)
 	#if defined XASH_MSVC || __LITTLE_ENDIAN__
 		//!!! Probably all WinNT installations runs in little endian
 		#define XASH_LITTLE_ENDIAN 1
diff --git a/scripts/waifulib/library_naming.py b/scripts/waifulib/library_naming.py
index 77dfa6df..827ef76c 100644
--- a/scripts/waifulib/library_naming.py
+++ b/scripts/waifulib/library_naming.py
@@ -49,7 +49,9 @@ DEFINES = [
 'XASH_OPENBSD',
 'XASH_WIN32',
 'XASH_WIN64',
-'XASH_X86'
+'XASH_X86',
+'XASH_DOS4GW',
+'XASH_POSIX'
 ]
 
 def configure(conf):
@@ -75,8 +77,11 @@ def configure(conf):
 		buildos = "openbsd"
 	elif conf.env.XASH_EMSCRIPTEN:
 		buildos = "emscripten"
+	elif conf.env.XASH_DOS4GW:
+		buildos = "dos4gw" # unused, just in case
 	else:
-		conf.fatal("Place your operating system name here! If this is a mistake, try to fix conditions above and report a bug")
+		conf.fatal("Place your operating system name in build.h and library_naming.py!\n"
+			"If this is a mistake, try to fix conditions above and report a bug")
 
 	if conf.env.XASH_AMD64:
 		buildarch = "amd64"
@@ -110,7 +115,8 @@ def configure(conf):
 	elif conf.env.XASH_E2K:
 		buildarch = "e2k"
 	else:
-		raise conf.fatal("Place your architecture name here! If this is a mistake, try to fix conditions above and report a bug")
+		raise conf.fatal("Place your architecture name in build.h and library_naming.py!\n"
+			"If this is a mistake, try to fix conditions above and report a bug")
 	
 	conf.env.revert()