diff --git a/packages/backend/src/models/user.ts b/packages/backend/src/models/user.ts
index fe58670c..20060458 100644
--- a/packages/backend/src/models/user.ts
+++ b/packages/backend/src/models/user.ts
@@ -263,6 +263,8 @@ class User extends Base {
 
   async $beforeInsert(queryContext: QueryContext) {
     await super.$beforeInsert(queryContext);
+
+    this.email = this.email.toLowerCase();
     await this.generateHash();
 
     if (appConfig.isCloud) {
@@ -273,6 +275,7 @@ class User extends Base {
   async $beforeUpdate(opt: ModelOptions, queryContext: QueryContext) {
     await super.$beforeUpdate(opt, queryContext);
 
+    this.email = this.email.toLowerCase();
     await this.generateHash();
   }