diff --git a/cmd/users.go b/cmd/users.go
index 2b8922f1..eba13442 100644
--- a/cmd/users.go
+++ b/cmd/users.go
@@ -13,7 +13,7 @@ import (
 )
 
 var (
-	reUsername = regexp.MustCompile(`^[a-zA-Z0-9_\\-\\.]+$`)
+	reUsername = regexp.MustCompile(`^[a-zA-Z0-9_\-\.@]+$`)
 )
 
 // GetUser retrieves a single user by ID.
diff --git a/frontend/src/views/UserForm.vue b/frontend/src/views/UserForm.vue
index af1a1bdc..e134dabf 100644
--- a/frontend/src/views/UserForm.vue
+++ b/frontend/src/views/UserForm.vue
@@ -45,7 +45,7 @@
         <b-field :label="$t('users.username')" label-position="on-border">
           <b-input :maxlength="200" v-model="form.username" name="username" ref="focus" autofocus
             :placeholder="$t('users.username')" required :message="$t('users.usernameHelp')" autocomplete="off"
-            pattern="[a-zA-Z0-9_\-\.]+$" />
+            pattern="[a-zA-Z0-9_\-\.@]+$" />
         </b-field>
 
         <b-field :label="$t('globals.fields.name')" label-position="on-border">