diff --git a/src/Ombi/Startup.cs b/src/Ombi/Startup.cs
index 9fd750da9..87600a3ca 100644
--- a/src/Ombi/Startup.cs
+++ b/src/Ombi/Startup.cs
@@ -94,6 +94,8 @@ namespace Ombi
                 options.Password.RequireLowercase = false;
                 options.Password.RequireNonAlphanumeric = false;
                 options.Password.RequireUppercase = false;
+                options.User.AllowedUserNameCharacters =
+                    "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789 -._@+";
             });
 
             services.AddDataProtection();