diff --git a/racket/src/worksp/csbuild.rkt b/racket/src/worksp/csbuild.rkt
index b4ee67386d..726fce4184 100644
--- a/racket/src/worksp/csbuild.rkt
+++ b/racket/src/worksp/csbuild.rkt
@@ -83,7 +83,7 @@
      (for ([submodule (in-list submodules)])
        (define dir (build-path scheme-dir submodule))
        (unless (directory-exists? (build-path dir ".git"))
-         (clone (format "~a~a/.git" submodule extra-repos-base)
+         (clone (format "~a~a/.git" extra-repos-base submodule)
                 (build-path scheme-dir submodule))))
      (when pull?
        (parameterize ([current-directory scheme-dir])