diff --git a/Gemfile b/Gemfile
index 5b45b8bdcc..719d65a2eb 100644
--- a/Gemfile
+++ b/Gemfile
@@ -50,9 +50,6 @@ gem "grape", "~> 0.6.1"
 gem "grape-entity", "~> 0.4.2"
 gem 'rack-cors', require: 'rack/cors'
 
-# Email validation
-gem "email_validator", "~> 1.4.0", :require => 'email_validator/strict'
-
 # Format dates and times
 # based on human-friendly examples
 gem "stamp"
diff --git a/Gemfile.lock b/Gemfile.lock
index 0d13ed5884..9e4dd35965 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -110,8 +110,6 @@ GEM
     email_spec (1.5.0)
       launchy (~> 2.1)
       mail (~> 2.2)
-    email_validator (1.4.0)
-      activemodel
     emoji (1.0.1)
       json
     enumerize (0.7.0)
@@ -591,7 +589,6 @@ DEPENDENCIES
   diffy (~> 3.0.3)
   dropzonejs-rails
   email_spec
-  email_validator (~> 1.4.0)
   enumerize
   factory_girl_rails
   ffaker
diff --git a/lib/email_validator.rb b/lib/email_validator.rb
new file mode 100644
index 0000000000..0a67ebcd79
--- /dev/null
+++ b/lib/email_validator.rb
@@ -0,0 +1,21 @@
+# Based on https://github.com/balexand/email_validator
+# 
+# Extended to use only strict mode with following allowed characters:
+# ' - apostrophe
+#
+# See http://www.remote.org/jochen/mail/info/chars.html
+#
+class EmailValidator < ActiveModel::EachValidator
+  @@default_options = {}
+
+  def self.default_options
+    @@default_options
+  end
+
+  def validate_each(record, attribute, value)
+    options = @@default_options.merge(self.options)
+    unless value =~ /\A\s*([-a-z0-9+._']{1,64})@((?:[-a-z0-9]+\.)+[a-z]{2,})\s*\z/i
+      record.errors.add(attribute, options[:message] || :invalid)
+    end
+  end
+end
diff --git a/spec/models/user_spec.rb b/spec/models/user_spec.rb
index 34a5bcfb4a..4e0ebb584d 100644
--- a/spec/models/user_spec.rb
+++ b/spec/models/user_spec.rb
@@ -83,11 +83,17 @@ describe User do
         user = build(:user, email: 'info@example.com')
         expect(user).to be_valid
       end
+
       it 'accepts info+test@example.com' do
         user = build(:user, email: 'info+test@example.com')
         expect(user).to be_valid
       end
 
+      it "accepts o'reilly@example.com" do
+        user = build(:user, email: "o'reilly@example.com")
+        expect(user).to be_valid
+      end
+
       it 'rejects test@test@example.com' do
         user = build(:user, email: 'test@test@example.com')
         expect(user).to be_invalid
@@ -97,6 +103,11 @@ describe User do
         user = build(:user, email: 'mailto:test@example.com')
         expect(user).to be_invalid
       end
+
+      it "rejects lol!'+=?><#$%^&*()@gmail.com" do
+        user = build(:user, email: "lol!'+=?><#$%^&*()@gmail.com")
+        expect(user).to be_invalid
+      end
     end
   end