diff --git a/fhem.pl b/fhem.pl
index dde566538..c9d678a4e 100755
--- a/fhem.pl
+++ b/fhem.pl
@@ -138,7 +138,7 @@ sub getPawList($);
 sub getUniqueId();
 sub hashKeyRename($$$);
 sub json2nameValue($;$$);
-sub json2reading($$;$$);
+sub json2reading($$;$$$);
 sub latin1ToUtf8($);
 sub myrename($$$);
 sub notifyRegexpChanged($$);