diff --git a/lib/solargraph/rbs_map/stdlib_map.rb b/lib/solargraph/rbs_map/stdlib_map.rb
index c713416a..624875d6 100644
--- a/lib/solargraph/rbs_map/stdlib_map.rb
+++ b/lib/solargraph/rbs_map/stdlib_map.rb
@@ -18,6 +18,9 @@ def initialize library
           pins.replace cache
         else
           super
+          if library == 'yaml'
+            pins.push Solargraph::Pin::Constant.new(name: 'YAML', comments: '@return [Module<Psych>]', closure: Pin::ROOT_PIN)
+          end
           Cache.save('stdlib', "#{library}.ser", pins)
         end
       end