diff --git a/lib/rubygems/remote_fetcher.rb b/lib/rubygems/remote_fetcher.rb
index 01788a6a5f17..8f5321847d0d 100644
--- a/lib/rubygems/remote_fetcher.rb
+++ b/lib/rubygems/remote_fetcher.rb
@@ -173,7 +173,7 @@ def download(spec, source_uri, install_dir = Gem.dir)
       end
 
       verbose "Using local gem #{local_gem_path}"
-    when nil then # TODO: test for local overriding cache
+    when nil then
       source_path = if Gem.win_platform? && source_uri.scheme &&
                        !source_uri.path.include?(":")
         "#{source_uri.scheme}:#{source_uri.path}"
diff --git a/test/rubygems/test_gem_remote_fetcher.rb b/test/rubygems/test_gem_remote_fetcher.rb
index 5c1d89fad693..ca6cb268fe6f 100644
--- a/test/rubygems/test_gem_remote_fetcher.rb
+++ b/test/rubygems/test_gem_remote_fetcher.rb
@@ -218,6 +218,24 @@ def test_download_local
     assert_equal @a1.cache_file, inst.download(@a1, local_path)
   end
 
+  def test_download_from_local_source_overrides_cache
+    omit "doesn't work if tempdir has +" if @tempdir.include?("+")
+
+    cache_path = @a1.cache_file
+    FileUtils.mkdir_p File.dirname(cache_path)
+    File.binwrite(cache_path, "outdated cache")
+
+    local_path = File.join(@tempdir, @a1.file_name)
+    FileUtils.cp(@a1_gem, local_path)
+
+    fetcher = Gem::RemoteFetcher.fetcher
+
+    stale_cache = File.binread(cache_path)
+    assert_equal cache_path, fetcher.download(@a1, local_path)
+    assert_equal File.binread(local_path), File.binread(cache_path)
+    refute_equal stale_cache, File.binread(cache_path)
+  end
+
   def test_download_local_space
     omit "doesn't work if tempdir has +" if @tempdir.include?("+")
     space_path = File.join @tempdir, "space path"