diff --git a/Gemfile.lock b/Gemfile.lock
index 47d3c86..2f951bd 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -9,13 +9,11 @@ GEM
   specs:
     diff-lcs (1.2.5)
     docile (1.1.5)
-    json (1.8.2)
     kjess (1.2.0)
     maildir (2.2.0)
     multi_json (1.10.1)
     rake (10.4.2)
-    rdoc (4.2.0)
-      json (~> 1.4)
+    rdoc (6.3.1)
     redis (3.2.1)
     rspec (3.2.0)
       rspec-core (~> 3.2.0)
@@ -43,7 +41,7 @@ DEPENDENCIES
   kjess (~> 1.2)
   qup!
   rake (~> 10.4)
-  rdoc (~> 4.0)
+  rdoc (~> 6.3)
   redis (~> 3.0)
   rspec (~> 3.2)
   simplecov (~> 0.9)
diff --git a/qup.gemspec b/qup.gemspec
index 758d0d0..109e49e 100644
--- a/qup.gemspec
+++ b/qup.gemspec
@@ -33,7 +33,7 @@ Gem::Specification.new do |s|
       s.add_development_dependency(%q<simplecov>, ["~> 0.9"])
       s.add_development_dependency(%q<rake>, ["~> 10.4"])
       s.add_development_dependency(%q<rspec>, ["~> 3.2"])
-      s.add_development_dependency(%q<rdoc>, ["~> 4.0"])
+      s.add_development_dependency(%q<rdoc>, "~> 6.3")
     else
       s.add_dependency(%q<maildir>, ["~> 2.2"])
       s.add_dependency(%q<kjess>, ["~> 1.2"])
@@ -41,7 +41,7 @@ Gem::Specification.new do |s|
       s.add_dependency(%q<simplecov>, ["~> 0.9"])
       s.add_dependency(%q<rake>, ["~> 10.4"])
       s.add_dependency(%q<rspec>, ["~> 3.2"])
-      s.add_dependency(%q<rdoc>, ["~> 4.0"])
+      s.add_dependency(%q<rdoc>, "~> 6.3")
     end
   else
     s.add_dependency(%q<maildir>, ["~> 2.2"])
@@ -50,6 +50,6 @@ Gem::Specification.new do |s|
     s.add_dependency(%q<simplecov>, ["~> 0.9"])
     s.add_dependency(%q<rake>, ["~> 10.4"])
     s.add_dependency(%q<rspec>, ["~> 3.2"])
-    s.add_dependency(%q<rdoc>, ["~> 4.0"])
+    s.add_dependency(%q<rdoc>, "~> 6.3")
   end
 end