diff --git a/examples/Gemfile.lock b/examples/Gemfile.lock
index f4797d51..407b3864 100644
--- a/examples/Gemfile.lock
+++ b/examples/Gemfile.lock
@@ -3,7 +3,7 @@ GEM
   specs:
     ruby-graphviz (1.0.0)
     state_machine (1.2.0)
-    yard (0.7.5)
+    yard (0.9.20)
 
 PLATFORMS
   ruby