diff --git a/Gemfile b/Gemfile
index 497e42ffc2..fb854ff9ca 100644
--- a/Gemfile
+++ b/Gemfile
@@ -3,6 +3,6 @@
 source 'https://rubygems.org'
 
 gem 'rake'
-gem 'yard'
+gem 'yard', "~> 0.9.36"
 gem 'yard-coderay'
 gem 'yard-mruby'
diff --git a/Gemfile.lock b/Gemfile.lock
index f017db738c..f1aa004380 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -2,10 +2,8 @@ GEM
   remote: https://rubygems.org/
   specs:
     coderay (1.1.3)
-    rake (13.1.0)
-    webrick (1.7.0)
-    yard (0.9.28)
-      webrick (~> 1.7.0)
+    rake (13.0.6)
+    yard (0.9.36)
     yard-coderay (0.1.0)
       coderay
       yard
@@ -19,7 +17,7 @@ PLATFORMS
 
 DEPENDENCIES
   rake
-  yard
+  yard (~> 0.9.36)
   yard-coderay
   yard-mruby