diff --git a/Gemfile b/Gemfile
index de9a62150..6969aba5b 100644
--- a/Gemfile
+++ b/Gemfile
@@ -63,7 +63,7 @@ end
 group :test do
     gem 'test-unit-full', '~> 0.0.5'
     gem 'rspec', '~> 3.13'
-    gem 'rdoc', '~> 6.12'
+    gem 'rdoc', '~> 6.13'
     gem 'browserstack-local', '~> 1.4'
 
     gem 'irb', '~> 1.15'
diff --git a/Gemfile.lock b/Gemfile.lock
index 7d28dad68..0daa35999 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -147,7 +147,7 @@ GEM
       rack (>= 1.3)
     rainbow (3.1.1)
     rake (13.2.1)
-    rdoc (6.12.0)
+    rdoc (6.13.0)
       psych (>= 4.0.0)
     regexp_parser (2.10.0)
     reline (0.6.0)
@@ -207,7 +207,7 @@ GEM
       tilt (~> 2.0)
     slack-notifier (2.4.0)
     sqlite3 (2.6.0-x86_64-linux-gnu)
-    stringio (3.1.2)
+    stringio (3.1.6)
     sync (0.5.0)
     term-ansicolor (1.11.2)
       tins (~> 1.0)
@@ -285,7 +285,7 @@ DEPENDENCIES
   rack (~> 2.2)
   rack-protection (~> 3.2.0)
   rake (~> 13.2)
-  rdoc (~> 6.12)
+  rdoc (~> 6.13)
   rest-client (~> 2.1.0)
   rspec (~> 3.13)
   rubocop (~> 1.75.1)