diff --git a/src/Umbraco.Web/Models/RegisterModel.cs b/src/Umbraco.Web/Models/RegisterModel.cs
index b51f09b631..2764d316b9 100644
--- a/src/Umbraco.Web/Models/RegisterModel.cs
+++ b/src/Umbraco.Web/Models/RegisterModel.cs
@@ -47,7 +47,7 @@ namespace Umbraco.Web.Models
         }
 
         [Required]
-        [RegularExpression(@"[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*@(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?",
+        [RegularExpression(@"[A-Za-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[A-Za-z0-9!#$%&'*+/=?^_`{|}~-]+)*@(?:[A-Za-z0-9](?:[A-Za-z0-9-]*[A-Za-z0-9])?\.)+[A-Za-z0-9](?:[A-Za-z0-9-]*[A-Za-z0-9])?",
             ErrorMessage = "Please enter a valid e-mail address")]
         public string Email { get; set; }