diff --git a/script/cronjobs/libki_nightly.pl b/script/cronjobs/libki_nightly.pl
index c6250a0..3513425 100755
--- a/script/cronjobs/libki_nightly.pl
+++ b/script/cronjobs/libki_nightly.pl
@@ -10,6 +10,7 @@
 use DateTime::Format::MySQL;
 use DateTime;
 use Getopt::Long::Descriptive;
+use JSON qw(to_json);
 use List::Util qw(max min);
 use Sys::Hostname;