diff --git a/Library/Homebrew/test/spec_helper.rb b/Library/Homebrew/test/spec_helper.rb
index 1c7c0fcdcd..97195fe819 100644
--- a/Library/Homebrew/test/spec_helper.rb
+++ b/Library/Homebrew/test/spec_helper.rb
@@ -43,9 +43,14 @@ RSpec.configure do |config|
 
   config.filter_run_when_matching :focus
 
-  config.expect_with :rspec do |c|
-    c.max_formatted_output_length = nil
-  end
+  # TODO when https://github.com/rspec/rspec-expectations/pull/1056 makes
+  # it into a stable release:
+  # config.expect_with :rspec do |c|
+  #   c.max_formatted_output_length = 200
+  # end
+
+  # Never truncate output objects.
+  RSpec::Support::ObjectFormatter.default_instance.max_formatted_output_length = nil
 
   config.include(FileUtils)