diff --git a/lib/mobility/plugins/active_model/dirty.rb b/lib/mobility/plugins/active_model/dirty.rb
index c8c2c65e5..4707e487b 100644
--- a/lib/mobility/plugins/active_model/dirty.rb
+++ b/lib/mobility/plugins/active_model/dirty.rb
@@ -15,7 +15,6 @@ module ActiveModel
 - +title_will_change!+
 - +title_previously_changed?+
 - +title_previous_change+
-- +title_previous_was+
 - +restore_title!+
 
 The following methods are also patched to work with translated attributes:
@@ -39,9 +38,6 @@ def initialize(*attribute_names)
 
             if ::ActiveModel::VERSION::STRING >= '5.0' # methods added in Rails 5.0
               define_ar_5_0_dirty_methods(attribute_names)
-              if ::ActiveModel::VERSION::STRING >= '5.1' # methods added in Rails 5.1
-                define_ar_6_0_dirty_methods(attribute_names)
-              end
             end
           end
 
@@ -107,16 +103,6 @@ def define_ar_5_0_dirty_methods(attribute_names)
             end
           end
 
-          def define_ar_6_0_dirty_methods(attribute_names)
-            m = self
-
-            attribute_names.each do |name|
-              define_method "#{name}_previously_was" do
-                mutations_before_last_save_from_mobility.original_value(m.append_locale(name))
-              end
-            end
-          end
-
           module InstanceMethods
             def changed_attributes
               super.merge(mutations_from_mobility.changed_values)
diff --git a/spec/mobility/plugins/active_model/dirty_spec.rb b/spec/mobility/plugins/active_model/dirty_spec.rb
index e612f2d91..f9ea4fa2d 100644
--- a/spec/mobility/plugins/active_model/dirty_spec.rb
+++ b/spec/mobility/plugins/active_model/dirty_spec.rb
@@ -165,10 +165,6 @@ def save
           expect(article.title_previously_changed?).to eq(true)
           expect(article.title_previous_change).to eq(["foo", "bar"])
           expect(article.title_changed?).to eq(false)
-
-          if ENV['RAILS_VERSION'].present? && ENV['RAILS_VERSION'] >= '6.0'
-            expect(article.title_previously_was).to eq('foo')
-          end
         end
 
         article.title_will_change!