diff --git a/gemfiles/truffleruby/Gemfile.lock b/gemfiles/truffleruby/Gemfile.lock
index 201cef9b95..d5bdc422fc 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 (3.6.2)
+    test-unit (3.6.4)
       power_assert
 
 PLATFORMS