diff --git a/lib/models/subscriptions.js b/lib/models/subscriptions.js
index 30d0625e..ca50b6db 100644
--- a/lib/models/subscriptions.js
+++ b/lib/models/subscriptions.js
@@ -1167,24 +1167,41 @@ module.exports.updateAddress = (list, cid, updates, optInIp, callback) => {
             let query = 'SELECT `id`, `email` FROM `subscription__' + list.id + '` WHERE `cid`=? LIMIT 1';
             let args = [cid];
             connection.query(query, args, (err, rows) => {
-                connection.release();
                 if (err) {
+                    connection.release();
                     return callback(err);
                 }
                 if (!rows || !rows.length) {
+                    connection.release();
                     return callback(new Error('Unknown subscription ID'));
                 }
 
                 if (rows[0].email === emailNew) {
+                    connection.release();
                     return callback(new Error('Nothing seems to be changed'));
                 }
 
-                module.exports.addConfirmation(list, emailNew, optInIp, {
-                    action: 'update',
-                    cid,
-                    subscriber: rows[0].id,
-                    emailOld: rows[0].email
-                }, callback);
+                let old = rows[0];
+
+                let query = 'SELECT `id` FROM `subscription__' + list.id + '` WHERE `email`=? AND `cid`<>? LIMIT 1';
+                let args = [emailNew, cid];
+                connection.query(query, args, (err, rows) => {
+                    connection.release();
+                    if (err) {
+                        return callback(err);
+                    }
+
+                    if (rows && rows[0] && rows[0].id) {
+                        return callback(new Error('This address is already registered by someone else'));
+                    }
+
+                    module.exports.addConfirmation(list, emailNew, optInIp, {
+                        action: 'update',
+                        cid,
+                        subscriber: old.id,
+                        emailOld: old.email
+                    }, callback);
+                });
             });
         });
     });