diff --git a/common/backends.h b/common/backends.h
index 8bcdc565..34c0f097 100644
--- a/common/backends.h
+++ b/common/backends.h
@@ -20,6 +20,8 @@ GNU General Public License for more details.
 #define VIDEO_SDL     1
 #define VIDEO_ANDROID 2
 #define VIDEO_FBDEV   3
+#define VIDEO_DOS     4
+
 
 // audio backends (XASH_SOUND)
 #define SOUND_NULL     0
@@ -44,6 +46,7 @@ GNU General Public License for more details.
 #define TIMER_SDL   1
 #define TIMER_LINUX 2
 #define TIMER_WIN32 3
+#define TIMER_DOS   4
 
 // messageboxes (XASH_MESSAGEBOX)
 #define MSGBOX_STDERR  0
diff --git a/common/defaults.h b/common/defaults.h
index 77603462..ab55d613 100644
--- a/common/defaults.h
+++ b/common/defaults.h
@@ -84,7 +84,17 @@ SETUP BACKENDS DEFINITIONS
 		#endif // XASH_SOUND
 
 		#define XASH_USE_EVDEV
-	#endif // XASH_LINUX
+	#elif XASH_DOS4GW
+		#ifndef XASH_VIDEO
+			#define XASH_VIDEO VIDEO_DOS
+		#endif
+		#ifndef XASH_TIMER
+			#define XASH_TIMER TIMER_DOS
+		#endif
+
+		// usually only 10-20 fds availiable
+		#define XASH_REDUCE_FD
+	#endif
 
 #endif // XASH_DEDICATED
 
@@ -126,9 +136,10 @@ SETUP BACKENDS DEFINITIONS
 #ifdef XASH_STATIC_LIBS
 #define XASH_LIB LIB_STATIC
 #define XASH_INTERNAL_GAMELIBS
+#define XASH_ALLOW_SAVERESTORE_OFFSETS
 #elif defined _WIN32
 #define XASH_LIB LIB_WIN32
-#else
+#elif XASH_POSIX
 #define XASH_LIB LIB_POSIX
 #endif
 
diff --git a/engine/common/build.c b/engine/common/build.c
index d124f18d..7fd62795 100644
--- a/engine/common/build.c
+++ b/engine/common/build.c
@@ -91,6 +91,8 @@ const char *Q_buildos( void )
 	osname = "openbsd";
 #elif XASH_EMSCRIPTEN
 	osname = "emscripten";
+#elif XASH_DOS4GW
+	osname = "DOS4GW";
 #else
 #error "Place your operating system name here! If this is a mistake, try to fix conditions above and report a bug"
 #endif
diff --git a/public/build.h b/public/build.h
index 746db765..7ae6ab07 100644
--- a/public/build.h
+++ b/public/build.h
@@ -98,6 +98,9 @@ GNU General Public License for more details.
 	#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