diff --git a/gemfiles/truffleruby/Gemfile.lock b/gemfiles/truffleruby/Gemfile.lock
index d5bdc422fc..8c546f7144 100644
--- a/gemfiles/truffleruby/Gemfile.lock
+++ b/gemfiles/truffleruby/Gemfile.lock
@@ -15,7 +15,7 @@ GEM
     rake (13.2.1)
     rake-compiler (1.2.8)
       rake
-    test-unit (3.6.4)
+    test-unit (3.6.5)
       power_assert
 
 PLATFORMS