diff --git a/Gemfile.lock b/Gemfile.lock
index 4158191..7cd01f3 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -2,6 +2,7 @@ PATH
   remote: .
   specs:
     un_used_methods (0.1.0)
+      thor (~> 1.0)
 
 GEM
   remote: https://rubygems.org/
@@ -48,6 +49,7 @@ GEM
       parser (>= 3.3.1.0)
     ruby-progressbar (1.13.0)
     strscan (3.1.0)
+    thor (1.3.1)
     unicode-display_width (2.5.0)
 
 PLATFORMS
diff --git a/un_used_methods.gemspec b/un_used_methods.gemspec
index aa1f76e..6ed6ea4 100644
--- a/un_used_methods.gemspec
+++ b/un_used_methods.gemspec
@@ -38,6 +38,7 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency "rake", "~> 13.0"
   spec.add_development_dependency "rspec", "~> 3.0"
   spec.add_development_dependency "rubocop", "~> 1.21"
+  spec.add_dependency "thor", "~> 1.0"
 
   # For more information and examples about making a new gem, check out our
   # guide at: https://bundler.io/guides/creating_gem.html