diff --git a/Gemfile.lock b/Gemfile.lock
index fe0b9e9..18cbd94 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -2,13 +2,9 @@ PATH
   remote: .
   specs:
     github_changelog_generator (1.12.0)
-      bundler (>= 1.7)
       colorize (~> 0.7)
       github_api (~> 0.12)
-      overcommit (>= 0.31)
       rake (>= 10.0)
-      rspec (>= 3.2)
-      rubocop (>= 0.31)
 
 GEM
   remote: https://rubygems.org/
@@ -40,11 +36,11 @@ GEM
       hashie (>= 3.4)
       multi_json (>= 1.7.5, < 2.0)
       oauth2
-    hashie (3.4.3)
+    hashie (3.4.4)
     iniparse (1.4.2)
     json (1.8.3)
     jwt (1.5.1)
-    multi_json (1.11.2)
+    multi_json (1.12.0)
     multi_xml (0.5.5)
     multipart-post (2.0.0)
     oauth2 (1.1.0)
@@ -53,15 +49,15 @@ GEM
       multi_json (~> 1.3)
       multi_xml (~> 0.5)
       rack (>= 1.2, < 3)
-    overcommit (0.32.0)
+    overcommit (0.33.0)
       childprocess (~> 0.5.8)
       iniparse (~> 1.4)
-    parser (2.3.0.6)
+    parser (2.3.1.0)
       ast (~> 2.2)
     powerpack (0.1.1)
     rack (1.6.4)
     rainbow (2.1.0)
-    rake (11.0.1)
+    rake (11.1.2)
     rspec (3.4.0)
       rspec-core (~> 3.4.0)
       rspec-expectations (~> 3.4.0)
@@ -75,13 +71,13 @@ GEM
       diff-lcs (>= 1.2.0, < 2.0)
       rspec-support (~> 3.4.0)
     rspec-support (3.4.1)
-    rubocop (0.38.0)
-      parser (>= 2.3.0.6, < 3.0)
+    rubocop (0.39.0)
+      parser (>= 2.3.0.7, < 3.0)
       powerpack (~> 0.1)
       rainbow (>= 1.99.1, < 3.0)
       ruby-progressbar (~> 1.7)
       unicode-display_width (~> 1.0, >= 1.0.1)
-    ruby-progressbar (1.7.5)
+    ruby-progressbar (1.8.0)
     simplecov (0.11.2)
       docile (~> 1.1.0)
       json (~> 1.8)
@@ -92,7 +88,7 @@ GEM
     thor (0.19.1)
     thread_safe (0.3.5)
     tins (1.6.0)
-    unicode-display_width (1.0.1)
+    unicode-display_width (1.0.5)
 
 PLATFORMS
   ruby
@@ -104,6 +100,7 @@ DEPENDENCIES
   github_changelog_generator!
   overcommit
   rake
+  rspec (>= 3.2)
   rubocop
   simplecov (~> 0.10)
 
diff --git a/github_changelog_generator.gemspec b/github_changelog_generator.gemspec
index a3f53dc..afa79b7 100644
--- a/github_changelog_generator.gemspec
+++ b/github_changelog_generator.gemspec
@@ -24,10 +24,11 @@ Gem::Specification.new do |spec|
   spec.require_paths = ["lib"]
 
   spec.add_runtime_dependency "rake", ">= 10.0"
-  spec.add_runtime_dependency "bundler", ">= 1.7"
   spec.add_runtime_dependency("github_api", ["~> 0.12"])
   spec.add_runtime_dependency("colorize", ["~> 0.7"])
-  spec.add_runtime_dependency("overcommit", ">= 0.31")
-  spec.add_runtime_dependency("rubocop", ">= 0.31")
-  spec.add_runtime_dependency("rspec", ">= 3.2")
+
+  spec.add_development_dependency("overcommit", ">= 0.31")
+  spec.add_development_dependency("rspec", ">= 3.2")
+  spec.add_development_dependency "bundler", ">= 1.7"
+  spec.add_development_dependency("rubocop", ">= 0.31")
 end