diff --git a/spec/ruby/security/cve_2019_8325_spec.rb b/spec/ruby/security/cve_2019_8325_spec.rb
index 04692e01fe..7c5e216568 100644
--- a/spec/ruby/security/cve_2019_8325_spec.rb
+++ b/spec/ruby/security/cve_2019_8325_spec.rb
@@ -5,8 +5,16 @@ require 'rubygems/command_manager'
 
 describe "CVE-2019-8325 is resisted by" do
   describe "sanitising error message components" do
+    silent_ui = Module.new do
+      attr_accessor :ui
+      def self.extended(obj)
+        obj.ui = Gem::SilentUI.new
+      end
+    end
+
     it "for the 'while executing' message" do
       manager = Gem::CommandManager.new
+      manager.extend(silent_ui)
       def manager.process_args(args, build_args)
         raise StandardError, "\e]2;nyan\a"
       end
@@ -26,6 +34,7 @@ describe "CVE-2019-8325 is resisted by" do
 
     it "for the 'loading command' message" do
       manager = Gem::CommandManager.new
+      manager.extend(silent_ui)
       def manager.require(x)
         raise 'foo'
       end