diff --git a/lib/sidekiq.rb b/lib/sidekiq.rb
index 93e103dc..81a50977 100644
--- a/lib/sidekiq.rb
+++ b/lib/sidekiq.rb
@@ -149,7 +149,11 @@ module Sidekiq
   end
 
   def self.default_worker_options=(hash)
-    @default_worker_options = default_worker_options.merge(hash.stringify_keys)
+    # stringify
+    hash.keys.each do |key|
+      hash[key.to_s] = hash.delete(key)
+    end
+    @default_worker_options = default_worker_options.merge(hash)
   end
   def self.default_worker_options
     defined?(@default_worker_options) ? @default_worker_options : DEFAULT_WORKER_OPTIONS
diff --git a/lib/sidekiq/core_ext.rb b/lib/sidekiq/core_ext.rb
index e4f36013..d862843e 100644
--- a/lib/sidekiq/core_ext.rb
+++ b/lib/sidekiq/core_ext.rb
@@ -73,24 +73,3 @@ rescue LoadError
 
   end
 end
-
-begin
-  require 'active_support/core_ext/hash/keys'
-rescue LoadError
-  class Hash
-    def stringify_keys
-      keys.each do |key|
-        self[key.to_s] = delete(key)
-      end
-      self
-    end if !{}.respond_to?(:stringify_keys)
-
-    def symbolize_keys
-      keys.each do |key|
-        self[(key.to_sym rescue key) || key] = delete(key)
-      end
-      self
-    end if !{}.respond_to?(:symbolize_keys)
-
-  end
-end
diff --git a/lib/sidekiq/redis_connection.rb b/lib/sidekiq/redis_connection.rb
index b1762666..c668d825 100644
--- a/lib/sidekiq/redis_connection.rb
+++ b/lib/sidekiq/redis_connection.rb
@@ -8,7 +8,9 @@ module Sidekiq
     class << self
 
       def create(options={})
-        options = options.symbolize_keys
+        options.keys.each do |key|
+          options[key.to_sym] = options.delete(key)
+        end
 
         options[:url] ||= determine_redis_provider
 
diff --git a/lib/sidekiq/web/helpers.rb b/lib/sidekiq/web/helpers.rb
index 2e0eba14..24811b1e 100644
--- a/lib/sidekiq/web/helpers.rb
+++ b/lib/sidekiq/web/helpers.rb
@@ -189,7 +189,11 @@ module Sidekiq
 
     # Merge options with current params, filter safe params, and stringify to query string
     def qparams(options)
-      options = options.stringify_keys
+      # stringify
+      options.keys.each do |key|
+        options[key.to_s] = options.delete(key)
+      end
+
       params.merge(options).map do |key, value|
         SAFE_QPARAMS.include?(key) ? "#{key}=#{CGI.escape(value.to_s)}" : next
       end.compact.join("&")
diff --git a/lib/sidekiq/worker.rb b/lib/sidekiq/worker.rb
index d400c71d..bf4b3b80 100644
--- a/lib/sidekiq/worker.rb
+++ b/lib/sidekiq/worker.rb
@@ -118,7 +118,12 @@ module Sidekiq
       # In practice, any option is allowed.  This is the main mechanism to configure the
       # options for a specific job.
       def sidekiq_options(opts={})
-        self.sidekiq_options_hash = get_sidekiq_options.merge(opts.stringify_keys)
+        # stringify
+        opts.keys.each do |key|
+          opts[key.to_s] = opts.delete(key)
+        end
+
+        self.sidekiq_options_hash = get_sidekiq_options.merge(opts)
       end
 
       def sidekiq_retry_in(&block)
@@ -135,8 +140,12 @@ module Sidekiq
 
       def client_push(item) # :nodoc:
         pool = Thread.current[:sidekiq_via_pool] || get_sidekiq_options['pool'.freeze] || Sidekiq.redis_pool
-        hash = item.stringify_keys
-        Sidekiq::Client.new(pool).push(hash)
+        # stringify
+        item.keys.each do |key|
+          item[key.to_s] = item.delete(key)
+        end
+
+        Sidekiq::Client.new(pool).push(item)
       end
 
     end