diff --git a/app/models/discourse_single_sign_on.rb b/app/models/discourse_single_sign_on.rb
index dae69d465a1..111a3a29517 100644
--- a/app/models/discourse_single_sign_on.rb
+++ b/app/models/discourse_single_sign_on.rb
@@ -66,6 +66,12 @@ class DiscourseSingleSignOn < SingleSignOn
       end
     end
 
+    if sso_record && (user = sso_record.user) && !user.active
+      user.active = true
+      user.save
+      user.enqueue_welcome_message('welcome_user')
+    end
+
     sso_record && sso_record.user
   end
 end
diff --git a/spec/controllers/session_controller_spec.rb b/spec/controllers/session_controller_spec.rb
index be225575a88..ada02e180c1 100644
--- a/spec/controllers/session_controller_spec.rb
+++ b/spec/controllers/session_controller_spec.rb
@@ -57,6 +57,7 @@ describe SessionController do
       logged_on_user.username.should == 'sam'
 
       logged_on_user.single_sign_on_record.external_id.should == "666"
+      logged_on_user.active.should == true
     end
 
     it 'allows login to existing account with valid nonce' do