diff --git a/nonguix/multiarch-container.scm b/nonguix/multiarch-container.scm
index 6cbd14a..8b54d40 100644
--- a/nonguix/multiarch-container.scm
+++ b/nonguix/multiarch-container.scm
@@ -335,6 +335,9 @@ in a sandboxed FHS environment."
                          ,@(exists-> (getenv "XAUTHORITY"))
                          #$@(ngc-shared container)))
                 (DEBUG (equal? (getenv "DEBUG") "1"))
+                (extra-shares (if (getenv "GUIX_SANDBOX_EXTRA_SHARES")
+                                  (string-split (getenv "GUIX_SANDBOX_EXTRA_SHARES") #\:)
+                                  #f))
                 (args (cdr (command-line)))
                 (command (if DEBUG '()
                              `("--" ,run ,@args))))
@@ -363,7 +366,9 @@ in a sandboxed FHS environment."
                     ,@(map add-path expose)
                     ,@(map (lambda (item)
                              (add-path item #:writable? #t))
-                           share)
+                           (if extra-shares
+                               (append share extra-shares)
+                               share))
                     "-m" ,manifest-file
                     ,@command)))))))