diff --git a/fhem/FHEM/73_GasCalculator.pm b/fhem/FHEM/73_GasCalculator.pm
index 20f01f08d..36bcc7c8c 100644
--- a/fhem/FHEM/73_GasCalculator.pm
+++ b/fhem/FHEM/73_GasCalculator.pm
@@ -54,6 +54,7 @@ use strict;
 use warnings;
 use Time::Local;
 use FHEM::Meta;
+use Data::Dumper;
 my %GasCalculator_gets;
 my %GasCalculator_sets;