diff --git a/sc2/build.vars.in b/sc2/build.vars.in
index 3a774a7d8..d97b1ea2f 100644
--- a/sc2/build.vars.in
+++ b/sc2/build.vars.in
@@ -39,8 +39,9 @@ uqm_HAVE_OPENGL='@HAVE_OPENGL@'
 uqm_USE_ZIP_IO='@USE_ZIP_IO@'
 uqm_USE_PLATFORM_ACCEL='@USE_PLATFORM_ACCEL@'
 uqm_NETPLAY='@NETPLAY@'
+uqm_USE_WINSOCK='@USE_WINSOCK@'
 DEBUG='@DEBUG@'
 export BUILD_SYSTEM HOST_SYSTEM DEBUG
 export MACRO_WIN32 MACRO__MCS_VER MACRO___MINGW32__
-export uqm_SOUNDMODULE uqm_USE_INTERNAL_MIKMOD uqm_HAVE_REGEX
+export uqm_SOUNDMODULE uqm_USE_INTERNAL_MIKMOD uqm_HAVE_REGEX uqm_USE_WINSOCK
 export uqm_HAVE_OPENGL uqm_USE_ZIP_IO uqm_USE_PLATFORM_ACCEL uqm_NETPLAY
diff --git a/sc2/build/unix/build.config b/sc2/build/unix/build.config
index ae2b07584..a8c18314c 100644
--- a/sc2/build/unix/build.config
+++ b/sc2/build/unix/build.config
@@ -49,11 +49,13 @@ uqm_requirements()
 	define_have_symbol getopt_long
 	define_have_header regex.h
 
-	# Add an environment variable for MACRO_WIN32, MACRO__MCS_VER, and
-	# MACRO___MINGW32__
+	# Add an environment variable for MACRO_WIN32 and MACRO___MINGW32__
 	define_have_macro WIN32
-	define_have_macro _MCS_VER
 	define_have_macro __MINGW32__
+
+	if [ -n "$MACRO___MINGW32__" ]; then
+		USE_WINSOCK=1
+	fi
 }
 
 uqm_prepare_config()
@@ -342,7 +344,7 @@ uqm_process_config() {
 			MAKE ECHON SED DEBUG JOYSTICK NETPLAY \
 			SOUNDMODULE USE_INTERNAL_MIKMOD \
 			HAVE_OPENGL HAVE_REGEX_H_FLAG USE_ZIP_IO \
-			USE_PLATFORM_ACCEL \
+			USE_PLATFORM_ACCEL USE_WINSOCK \
 			INSTALL_LIBDIR INSTALL_BINDIR INSTALL_SHAREDIR \
 			REZ WINDRES"
 	SUBSTITUTE_FILES="build.vars"