diff --git a/data/Dockerfiles/dovecot/imapsync_cron.pl b/data/Dockerfiles/dovecot/imapsync_cron.pl
index 8bc3d976..2b61545e 100644
--- a/data/Dockerfiles/dovecot/imapsync_cron.pl
+++ b/data/Dockerfiles/dovecot/imapsync_cron.pl
@@ -5,11 +5,11 @@ use LockFile::Simple qw(lock trylock unlock);
 use Proc::ProcessTable;
 use Data::Dumper qw(Dumper);
 use IPC::Run 'run';
-use String::Util 'trim';
 use File::Temp;
 use Try::Tiny;
 use sigtrap 'handler' => \&sig_handler, qw(INT TERM KILL QUIT);
 
+sub trim { my $s = shift; $s =~ s/^\s+|\s+$//g; return $s };
 my $t = Proc::ProcessTable->new;
 my $imapsync_running = grep { $_->{cmndline} =~ /^\/usr\/bin\/perl \/usr\/local\/bin\/imapsync\s/ } @{$t->table};
 if ($imapsync_running eq 1)