diff --git a/config.sub b/config.sub
index 004c7de..8c16a0e 100755
--- a/config.sub
+++ b/config.sub
@@ -995,7 +995,8 @@
 	      | -cygwin* | -pe* | -psos* | -moss* | -proelf* | -rtems* \
 	      | -mingw32* | -linux-gnu* | -uxpv* | -beos* | -mpeix* | -udk* \
 	      | -interix* | -uwin* | -rhapsody* | -darwin* | -opened* \
-	      | -openstep* | -oskit* | -conix* | -pw32* | -nonstopux* | -storm-chaos*)
+	      | -openstep* | -oskit* | -conix* | -pw32* | -nonstopux* \
+        | -storm-chaos* | -sixos*)
 	# Remember, each alternative MUST END IN *, to match a version number.
 		;;
 	-qnx*)