diff --git a/lib/sidekiq/core_ext.rb b/lib/sidekiq/core_ext.rb
index ef12ae6c..cc4b0ed7 100644
--- a/lib/sidekiq/core_ext.rb
+++ b/lib/sidekiq/core_ext.rb
@@ -60,8 +60,15 @@ rescue LoadError
         self[key.to_s] = delete(key)
       end
       self
-    end
-  end if !{}.respond_to?(:stringify_keys)
+    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
 
 begin