diff --git a/config/initializers/secure_headers.rb b/config/initializers/secure_headers.rb
index a7900165f9b..f805ff60a33 100644
--- a/config/initializers/secure_headers.rb
+++ b/config/initializers/secure_headers.rb
@@ -46,6 +46,10 @@
 
   default_csp_config[:script_src] = ["'self'", "'unsafe-eval'"] if !Rails.env.production?
 
+  if IdentityConfig.store.rails_mailer_previews_enabled
+    default_csp_config[:style_src] << "'unsafe-inline'"
+  end
+
   config.csp = default_csp_config
 
   if ENV['WEBPACK_PORT']