diff --git a/Gemfile b/Gemfile
index 328983b..1c5886d 100644
--- a/Gemfile
+++ b/Gemfile
@@ -15,7 +15,7 @@ group :development do
   gem 'irb'
   gem 'rake', '>= 12.3.3'
   gem 'rubocop', '~> 1'
-  gem 'yard', '~> 0.9.36'
+  gem 'yard', '~> 0.9.42'
 end
 
 group :test do
diff --git a/Gemfile.lock b/Gemfile.lock
index 9644df8..5977404 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -30,10 +30,8 @@ GEM
       pry (>= 0.13.0)
       shellany (~> 0.0)
       thor (>= 0.18.1)
-    guard-bundler (3.0.1)
-      bundler (>= 2.1, < 3)
-      guard (~> 2.2)
-      guard-compat (~> 1.1)
+    guard-bundler (0.1.2)
+      guard (>= 0.2.2)
     guard-compat (1.2.1)
     guard-inch (0.2.0)
       guard (~> 2)
@@ -145,7 +143,7 @@ GEM
     unicode-display_width (3.1.4)
       unicode-emoji (~> 4.0, >= 4.0.4)
     unicode-emoji (4.0.4)
-    yard (0.9.37)
+    yard (0.9.42)
 
 PLATFORMS
   ruby
@@ -164,7 +162,7 @@ DEPENDENCIES
   rspec (~> 3.4)
   rubocop (~> 1)
   simplecov (> 0.20)
-  yard (~> 0.9.36)
+  yard (~> 0.9.42)
 
 BUNDLED WITH
    2.7.1