diff -r 3933eebc659d -r ffb4d2e95140 common/autoconf/spec.gmk.in
--- a/common/autoconf/spec.gmk.in	Thu Feb 07 12:32:32 2013 -0800
+++ b/common/autoconf/spec.gmk.in	Fri Feb 15 10:40:46 2013 +0100
@@ -282,6 +282,9 @@
 X_LIBS:=@X_LIBS@
 OPENWIN_HOME:=@OPENWIN_HOME@
 
+# The lowest required version of macosx to enforce compatiblity for
+MACOSX_REQUIRED_VERSION=@MACOSX_REQUIRED_VERSION@
+
 # There are two types: CC or CL
 # CC is gcc and others behaving reasonably similar.
 # CL is cl.exe only.