diff --git a/lib/puma/configuration.rb b/lib/puma/configuration.rb
index 0dbd47df..ff4595d9 100644
--- a/lib/puma/configuration.rb
+++ b/lib/puma/configuration.rb
@@ -104,9 +104,9 @@ module Puma
       rack_app, rack_options = Puma::Rack::Builder.parse_file(rackup)
       @options.merge!(rack_options)
 
-      config_ru_binds = rack_options.inject([]) do |b, (k, v)|
-        b << v if k.to_s.start_with?("bind")
-        b
+      config_ru_binds = []
+      rack_options.each do |k, v|
+        config_ru_binds << v if k.to_s.start_with?("bind")
       end
       @options[:binds] = config_ru_binds unless config_ru_binds.empty?