diff --git a/Library/Homebrew/test/download_strategies/abstract_spec.rb b/Library/Homebrew/test/download_strategies/abstract_spec.rb
index e58b15b49f..c56451daed 100644
--- a/Library/Homebrew/test/download_strategies/abstract_spec.rb
+++ b/Library/Homebrew/test/download_strategies/abstract_spec.rb
@@ -12,7 +12,7 @@ RSpec.describe AbstractDownloadStrategy do
   let(:args) { %w[foo bar baz] }
 
   specify "#source_modified_time" do
-    Mktemp.new("mtime") do
+    mktmpdir("mtime").cd do
       FileUtils.touch "foo", mtime: Time.now - 10
       FileUtils.touch "bar", mtime: Time.now - 100
       FileUtils.ln_s "not-exist", "baz"