diff --git a/extra/mason/child/child.factor b/extra/mason/child/child.factor
index 92717f6296..95974b8852 100644
--- a/extra/mason/child/child.factor
+++ b/extra/mason/child/child.factor
@@ -10,7 +10,7 @@ IN: mason.child
 ! Make sure we call the build directory's factor.cmd
 : nmake-cmd ( -- args )
     "./build-support/factor.cmd" absolute-path
-    target-cpu get name>> "." split "-" join suffix ;
+    target-cpu get name>> "." split "-" join 2array ;
 
 : gnu-make-cmd ( -- args )
     gnu-make