diff --git a/Gemfile.lock b/Gemfile.lock
index eb65157c8cf59d13b93e5ad75a84c6b46cc95e0d..94e7d2a26f00f96b4732598a4055758f15aa5c1c 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -57,7 +57,7 @@ GEM
       ast (~> 2.4.0)
     rainbow (3.0.0)
     rake (11.3.0)
-    rdoc (4.3.0)
+    rdoc (6.3.2)
     require_all (2.0.0)
     rexml (3.2.4)
     rspec-expectations (3.9.1)
@@ -86,7 +86,7 @@ DEPENDENCIES
   bundler (~> 2.0)
   json (~> 1.8)
   rake (~> 11.3)
-  rdoc (~> 4.2)
+  rdoc (~> 6.3)
   rubocop (~> 0.82)
 
 BUNDLED WITH
diff --git a/aethyr.gemspec b/aethyr.gemspec
index 7dcbf938e94edb111acc90199bfe47a21aa509b6..62fa70f46abba9e18419fa154fedeb0cacac039e 100644
--- a/aethyr.gemspec
+++ b/aethyr.gemspec
@@ -38,7 +38,7 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency 'bundler', '~> 2.0'
   spec.add_development_dependency 'json', '~> 1.8'
   spec.add_development_dependency 'rake', '~> 11.3'
-  spec.add_development_dependency 'rdoc', '~> 4.2'
+  spec.add_development_dependency 'rdoc', '~> 6.3'
   spec.add_development_dependency 'aruba', '~> 0.14'
   spec.add_development_dependency 'rubocop', '~> 0.82'
 end