diff --git a/fhem/FHEM/73_GasCalculator.pm b/fhem/FHEM/73_GasCalculator.pm
index 2959aff85..356a0ce65 100644
--- a/fhem/FHEM/73_GasCalculator.pm
+++ b/fhem/FHEM/73_GasCalculator.pm
@@ -46,6 +46,7 @@ use strict;
 use warnings;
 my %GasCalculator_gets;
 my %GasCalculator_sets;
+use Time::Local;
 use FHEM::Meta;
 
 ###START###### Initialize module ##############################################################################START####