diff --git a/lib/fluent/event_router.rb b/lib/fluent/event_router.rb
index 9a133b5c6b..61793dcdd3 100644
--- a/lib/fluent/event_router.rb
+++ b/lib/fluent/event_router.rb
@@ -286,7 +286,7 @@ def reset_optimization
 
     def find(tag)
       pipeline = nil
-      @match_rules.each_with_index { |rule, i|
+      @match_rules.each do |rule|
         if rule.match?(tag)
           if rule.collector.is_a?(Plugin::Filter)
             pipeline ||= Pipeline.new