diff --git a/Gemfile b/Gemfile
index b850c1c..ffc027d 100644
--- a/Gemfile
+++ b/Gemfile
@@ -8,7 +8,7 @@ source "https://rubygems.org"
 group :development do
   gem "rspec", "~> 3.7.0"
   gem 'rspec-its'
-  gem "rdoc", "~> 6.0.1"
+  gem "rdoc", "~> 6.3.4", ">= 6.3.4.1"
   gem "bundler", "~> 1.6"
   gem "juwelier"
   gem "simplecov", "~> 0.15.1"
diff --git a/Gemfile.lock b/Gemfile.lock
index c986c61..ee79654 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -99,7 +99,7 @@ GEM
     rack (3.0.4.1)
     rake (13.0.6)
     rchardet (1.8.0)
-    rdoc (6.0.4)
+    rdoc (6.3.4.1)
     rspec (3.7.0)
       rspec-core (~> 3.7.0)
       rspec-expectations (~> 3.7.0)
@@ -134,7 +134,7 @@ DEPENDENCIES
   codeclimate-test-reporter
   cucumber
   juwelier
-  rdoc (~> 6.0.1)
+  rdoc (~> 6.3.4, >= 6.3.4.1)
   rspec (~> 3.7.0)
   rspec-its
   simplecov (~> 0.15.1)