diff --git a/lib/octocatalog-diff/catalog-util/git.rb b/lib/octocatalog-diff/catalog-util/git.rb
index 0d77533f..ad2c0d61 100644
--- a/lib/octocatalog-diff/catalog-util/git.rb
+++ b/lib/octocatalog-diff/catalog-util/git.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require 'rugged'
+require 'git'
 
 require_relative '../errors'
 require_relative '../util/scriptrunner'
@@ -64,8 +64,8 @@ def self.branch_sha(options = {})
         if dir.nil? || !File.directory?(dir)
           raise Errno::ENOENT, "Git directory #{dir.inspect} does not exist"
         end
-        repo = Rugged::Repository.new(dir)
-        repo.branches[branch].target_id
+        repo = ::Git.open(dir)
+        repo.branch(branch).gcommit.sha
       end
     end
   end
diff --git a/octocatalog-diff.gemspec b/octocatalog-diff.gemspec
index 92245a50..db32ae96 100644
--- a/octocatalog-diff.gemspec
+++ b/octocatalog-diff.gemspec
@@ -29,7 +29,7 @@ EOF
   s.add_runtime_dependency 'httparty', '>= 0.21.0'
   s.add_runtime_dependency 'hashdiff', '>= 0.3.0'
   s.add_runtime_dependency 'parallel', '>= 1.12.0'
-  s.add_runtime_dependency 'rugged', '>= 0.25.0b2'
+  s.add_runtime_dependency 'git', '~> 4'
   s.add_runtime_dependency 'puppet', '>= 5.5.0'
   s.add_development_dependency 'puppet', '>= 5.5.0'
   s.add_development_dependency 'rspec', '~> 3.4.0'
diff --git a/rake/doc.rb b/rake/doc.rb
index bfdcb193..3016c917 100644
--- a/rake/doc.rb
+++ b/rake/doc.rb
@@ -1,6 +1,5 @@
 require 'erb'
 require 'optparse'
-require 'rugged'
 
 require_relative '../lib/octocatalog-diff/cli/options'
 require_relative '../lib/octocatalog-diff/version'
diff --git a/spec/octocatalog-diff/tests/catalog-util/cached_master_directory_spec.rb b/spec/octocatalog-diff/tests/catalog-util/cached_master_directory_spec.rb
index dbce58ce..2795023e 100644
--- a/spec/octocatalog-diff/tests/catalog-util/cached_master_directory_spec.rb
+++ b/spec/octocatalog-diff/tests/catalog-util/cached_master_directory_spec.rb
@@ -4,9 +4,9 @@
 require OctocatalogDiff::Spec.require_path('/catalog-util/cached_master_directory')
 
 require 'fileutils'
+require 'git'
 require 'json'
 require 'open3'
-require 'rugged'
 require 'tmpdir'
 
 describe OctocatalogDiff::CatalogUtil::CachedMasterDirectory do
@@ -66,9 +66,9 @@
 
     it 'should have the expected SHA returned by rugged' do
       pending 'repository checkout fixture missing' unless File.directory?(@default_options[:basedir])
-      repo = Rugged::Repository.new(@default_options[:basedir])
-      test_rugged_sha = repo.branches['master'].target_id
-      expect(test_rugged_sha).to eq(@master_sha)
+      repo = Git.open(@default_options[:basedir])
+      test_git_sha = repo.branch('master').gcommit.sha
+      expect(test_git_sha).to eq(@master_sha)
     end
   end
 
diff --git a/spec/octocatalog-diff/tests/catalog-util/git_spec.rb b/spec/octocatalog-diff/tests/catalog-util/git_spec.rb
index 2ca7575c..4c096d6f 100644
--- a/spec/octocatalog-diff/tests/catalog-util/git_spec.rb
+++ b/spec/octocatalog-diff/tests/catalog-util/git_spec.rb
@@ -13,6 +13,7 @@
     @logger, @logger_str = OctocatalogDiff::Spec.setup_logger
     allow(File).to receive(:'directory?').with('/tmp/foo').and_return(false)
     allow(File).to receive(:'directory?').with('/tmp/bar').and_return(true)
+    allow(File).to receive(:'directory?').with('.').and_return(true)
   end
 
   describe '#check_out_git_archive' do
@@ -93,14 +94,10 @@
     end
 
     context 'with valid directory' do
-      it 'should return the sha from rugged' do
-        opts = { branch: 'foo', basedir: '/tmp/bar' }
-        expect(Rugged::Repository).to receive(:new).with('/tmp/bar')
-                                                   .and_return(OpenStruct.new(branches: {
-                                                                                'foo' => OpenStruct.new(target_id: 'abcdef012345')
-                                                                              }))
+      it 'should return the sha' do
+        opts = { branch: 'master', basedir: '.' }
         result = described_class.branch_sha(opts)
-        expect(result).to eq('abcdef012345')
+        expect(result).to match(/^[0-9a-f]+$/)
       end
     end
   end