diff --git a/db/migrate/20140521220115_google_openid_default_has_changed.rb b/db/migrate/20140521220115_google_openid_default_has_changed.rb
index 4d154073d..a9964bafd 100644
--- a/db/migrate/20140521220115_google_openid_default_has_changed.rb
+++ b/db/migrate/20140521220115_google_openid_default_has_changed.rb
@@ -8,6 +8,12 @@ class GoogleOpenidDefaultHasChanged < ActiveRecord::Migration
         # The old default was true, so add a row to keep it that way.
         execute "INSERT INTO site_settings (name, data_type, value, created_at, updated_at) VALUES ('enable_google_logins', 5, 't', now(), now())"
       end
+
+      # Don't enable the new Google setting on an existing site.
+      result = User.exec_sql("SELECT count(*) FROM site_settings WHERE name = 'enable_google_oauth2_logins'")
+      if result[0]['count'].to_i == 0
+        execute "INSERT INTO site_settings (name, data_type, value, created_at, updated_at) VALUES ('enable_google_oauth2_logins', 5, 'f', now(), now())"
+      end
     end
   end