1 files changed, 7 insertions, 1 deletions
diff --git a/activemodel/lib/active_model/dirty.rb b/activemodel/lib/active_model/dirty.rb
index aaefe00c83..245616502d 100644
--- a/activemodel/lib/active_model/dirty.rb
+++ b/activemodel/lib/active_model/dirty.rb
@@ -84,6 +84,7 @@ module ActiveModel
   #   person.previous_changes         # => {"name" => [nil, "Bill"]}
   #   person.name_previously_changed? # => true
   #   person.name_previous_change     # => [nil, "Bill"]
+  #   person.name_previously_was      # => nil
   #   person.reload!
   #   person.previous_changes         # => {}
   #
@@ -122,7 +123,7 @@ module ActiveModel
 
     included do
       attribute_method_suffix "_changed?", "_change", "_will_change!", "_was"
-      attribute_method_suffix "_previously_changed?", "_previous_change"
+      attribute_method_suffix "_previously_changed?", "_previous_change", "_previously_was"
       attribute_method_affix prefix: "restore_", suffix: "!"
     end
 
@@ -180,6 +181,11 @@ module ActiveModel
       mutations_before_last_save.changed?(attr_name.to_s)
     end
 
+    # Dispatch target for <tt>*_previously_was</tt> attribute methods.
+    def attribute_previously_was(attr_name) # :nodoc:
+      mutations_before_last_save.original_value(attr_name.to_s)
+    end
+
     # Restore all previous data of the provided attributes.
     def restore_attributes(attr_names = changed)
       attr_names.each { |attr_name| restore_attribute!(attr_name) }