diff --git a/src/groups/membership.js b/src/groups/membership.js
index c8cf9a9871..8a769b71df 100644
--- a/src/groups/membership.js
+++ b/src/groups/membership.js
@@ -44,6 +44,10 @@ module.exports = function(Groups) {
 
 		callback = callback || function() {};
 
+		if (!groupName || !parseInt(uid, 10)) {
+			return callback(new Error('[[error:invalid-data]]'));
+		}
+
 		Groups.exists(groupName, function(err, exists) {
 			if (err) {
 				return callback(err);