diff --git a/activesupport/lib/active_support/core_ext/array/prepend_and_append.rb b/activesupport/lib/active_support/core_ext/array/prepend_and_append.rb
index 16a6789f8d..88a34128c9 100644
--- a/activesupport/lib/active_support/core_ext/array/prepend_and_append.rb
+++ b/activesupport/lib/active_support/core_ext/array/prepend_and_append.rb
@@ -1,7 +1,7 @@
 class Array
   # The human way of thinking about adding stuff to the end of a list is with append.
-  alias_method :append,  :<<
+  alias_method :append,  :push unless [].respond_to?(:append)
 
   # The human way of thinking about adding stuff to the beginning of a list is with prepend.
-  alias_method :prepend, :unshift
+  alias_method :prepend, :unshift unless [].respond_to?(:prepend)
 end