diff --git a/app/models/user.rb b/app/models/user.rb
index 7bb67e8..c422e28 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -18,7 +18,7 @@ class User < ActiveRecord::Base
   validates_length_of :about, maximum: 5000
   validates_length_of :ign, minimum: 1, maximum: 16
 
-  validates :email, uniqueness: {case_sensitive: false}, format: {with: /\A.+@(.+\..{2,}|\[[0-9a-f:.]+\])\z/i, message: "That doesn't look like an email address."}
+  validates :email, uniqueness: {case_sensitive: false}, format: {with: /\A.+@(.+\..{2,}|\[(IPv6)?[0-9a-f:.]+\])\z/i, message: "That doesn't look like an email address."}
   validates :ign, uniqueness: {case_sensitive: false}, format: {with: /\A[a-z\d_]+\z/i, message: "Username is invalid (a-z, 0-9, _)."}
 
   has_many :blogposts