diff --git a/tk/mcron.scm b/tk/mcron.scm
index b805150..69af2e9 100644
--- a/tk/mcron.scm
+++ b/tk/mcron.scm
@@ -4,6 +4,8 @@
             step-from
             str->secs
             strf->secs
+            current-date-string
+            yesterday-date-string
             )
   #:use-module (srfi srfi-19)
   #:duplicates (warn-override-core warn))