diff --git a/racket/src/worksp/csbuild.rkt b/racket/src/worksp/csbuild.rkt
index dd2b57322a..8bb2276a79 100644
--- a/racket/src/worksp/csbuild.rkt
+++ b/racket/src/worksp/csbuild.rkt
@@ -172,12 +172,19 @@
 
 ;; ----------------------------------------
 
-;; The library name changes with the version:
+;; The library name changes with the version, so extract it from the
+;; Chez Scheme makefile
 (define scheme-lib
-  (parameterize ([current-directory (build-path scheme-dir machine "boot" machine)])
-    (for/or ([f (in-list (directory-list))]
-	     #:when (regexp-match? #rx"^csv.*mt.lib$" f))
-      f)))
+  (let ()
+    (define name
+      (call-with-input-file*
+       (build-path scheme-dir "c" (format "Makefile.~a" machine))
+       (lambda (i)
+         (for/or ([l (in-lines i)])
+           (define m (regexp-match #rx"MTKernelLib *= *.*(csv.*mt.lib)" l))
+           (and m
+                (cadr m))))))
+    (build-path scheme-dir machine "boot" machine name)))
 
 (define rel2-scheme-dir (build-path 'up
 				    (if (relative-path? scheme-dir)