diff --git a/libs/data.sld b/libs/data.sld
index aa35287..6961c31 100644
--- a/libs/data.sld
+++ b/libs/data.sld
@@ -149,6 +149,10 @@
           (type . compiler)
           (library-command . ,(lambda (library-file prepend-directories append-directories r6rs?)
                                 (apply string-append `("gsc -obj "
+                                                       ,@(map (lambda (item)
+                                                                (string-append item "/ "))
+                                                              (append prepend-directories
+                                                                      append-directories))
                                                        ,@(map (lambda (item)
                                                                 (string-append item "/ "))
                                                               (append prepend-directories