diff --git a/basis/calendar/calendar-tests.factor b/basis/calendar/calendar-tests.factor
index 44ba777c45..9c45ee0107 100644
--- a/basis/calendar/calendar-tests.factor
+++ b/basis/calendar/calendar-tests.factor
@@ -1,5 +1,6 @@
 USING: arrays calendar kernel math sequences tools.test
-continuations system math.order threads accessors ;
+continuations system math.order threads accessors
+random ;
 IN: calendar.tests
 
 [ f ] [ 2004 12 32 0   0  0 instant <timestamp> valid-timestamp? ] unit-test