Index: configure.ac
==================================================================
--- configure.ac
+++ configure.ac
@@ -142,10 +142,18 @@
 *-*-mint*)
 	enable_shared="no"
 	enable_threads="no"	# TODO
 	with_tls="no"
 	;;
+*-apple-macos*)
+	enable_shared="no"
+	enable_threads="no"	# TODO
+	enable_sockets="no"	# TODO
+
+	AC_DEFINE(OF_CLASSIC_MACOS, 1,
+		[Whether we are compiling for classic macOS])
+	;;
 esac
 
 AS_IF([test x"$host_os" = x"msdosdjgpp" -a x"$build_os" = x"msdosdjgpp"], [
 	dnl Hack to make configure find these on DOS.
 	: ${AR:=ar.exe}

Index: src/objfw-defs.h.in
==================================================================
--- src/objfw-defs.h.in
+++ src/objfw-defs.h.in
@@ -1,7 +1,8 @@
 #undef OF_APPLE_RUNTIME
 #undef OF_BIG_ENDIAN
+#undef OF_CLASSIC_MACOS
 #undef OF_FLOAT_BIG_ENDIAN
 #undef OF_HAVE_AFUNIX_H
 #undef OF_HAVE_APPLETALK
 #undef OF_HAVE_ATOMIC_BUILTINS
 #undef OF_HAVE_ATOMIC_OPS