--- a/makelib/definitions-w.make	Mon Aug 14 21:08:20 2017 +0100
+++ b/makelib/definitions-w.make	Tue Aug 15 10:44:12 2017 +0100
@@ -14,6 +14,19 @@
 #   USETCC=1     - tiny-C (tcc)   (suspended work - unfinished)
 #   USEMINGW64=1 - mingw-C        (ongoing work)
 
+!ifndef BUILD_TARGET
+! ifdef USEMINGW32
+BUILD_TARGET = i686-pc-mingw32
+! else
+!  ifdef USEMINGW64
+BUILD_TARGET = x86_64-w64-mingw32
+!  else
+BUILD_TARGET = unknown-unknown-unknown
+!  endif
+! endif
+!endif
+
+
 !ifdef USEVC
 ! undef USEBC
 !endif