Index: configure.ac
==================================================================
--- configure.ac
+++ configure.ac
@@ -618,11 +618,11 @@
 AC_ARG_ENABLE(sockets,
 	AS_HELP_STRING([--disable-sockets], [disable socket support]))
 AS_IF([test x"$enable_sockets" != x"no"], [
 	AC_DEFINE(OF_HAVE_SOCKETS, 1, [Whether we have sockets])
 	AC_SUBST(USE_SRCS_SOCKETS, '${SRCS_SOCKETS}')
-	AC_SUBST(USE_INCLUDES_SOCKETS, '${INCLUDES_SOCKET}')
+	AC_SUBST(USE_INCLUDES_SOCKETS, '${INCLUDES_SOCKETS}')
 
 	AC_CHECK_LIB(socket, socket, LIBS="$LIBS -lsocket")
 	AC_CHECK_LIB(network, socket, LIBS="$LIBS -lnetwork")
 	AC_CHECK_LIB(ws2_32, main, LIBS="$LIBS -lws2_32")
 

Index: extra.mk.in
==================================================================
--- extra.mk.in
+++ extra.mk.in
@@ -45,10 +45,11 @@
 RUNTIME_LIB_A = @RUNTIME_LIB_A@
 TESTPLUGIN = @TESTPLUGIN@
 TESTS = @TESTS@
 TESTS_LIBS = @TESTS_LIBS@
 TEST_LAUNCHER = @TEST_LAUNCHER@
+USE_INCLUDES_SOCKETS = @USE_INCLUDES_SOCKETS@
 USE_INCLUDES_THREADS = @USE_INCLUDES_THREADS@
 USE_SRCS_FILES = @USE_SRCS_FILES@
 USE_SRCS_PLUGINS = @USE_SRCS_PLUGINS@
 USE_SRCS_SOCKETS = @USE_SRCS_SOCKETS@
 USE_SRCS_THREADS = @USE_SRCS_THREADS@