monitor.diff

diff --git a/lib/ruby/stdlib/monitor.rb b/lib/ruby/stdlib/monitor.rb
index 26b976b860a..a6661cbf98f 100644
--- a/lib/ruby/stdlib/monitor.rb
+++ b/lib/ruby/stdlib/monitor.rb
@@ -226,7 +226,7 @@ module MonitorMixin
   # of this constructor.  Have look at the examples above to understand how to
   # use this module.
   def initialize(...)
-    super
+    super(...)
     mon_initialize
   end