--- a/mod_adhoc_groups/mod_adhoc_groups.lua	Wed May 20 17:24:15 2020 +0200
+++ b/mod_adhoc_groups/mod_adhoc_groups.lua	Wed May 20 17:25:59 2020 +0200
@@ -131,7 +131,7 @@
 						return false, "No such group";
 					end
 				end
-				if group[data.from] then
+				if group[user] then
 					return false, "You are already in this group.";
 				end