diff --git a/fhem/FHEM/57_Calendar.pm b/fhem/FHEM/57_Calendar.pm
index 9b1e60654..942528870 100644
--- a/fhem/FHEM/57_Calendar.pm
+++ b/fhem/FHEM/57_Calendar.pm
@@ -31,6 +31,8 @@ use HttpUtils;
 
 package main;
 
+no if $] >= 5.017011, warnings => 'experimental::smartmatch';
+
 #
 # *** Potential isses:
 #