diff --git a/activerecord/CHANGELOG.md b/activerecord/CHANGELOG.md
index 7a03d4f9e1..1c85197ec7 100644
--- a/activerecord/CHANGELOG.md
+++ b/activerecord/CHANGELOG.md
@@ -1,3 +1,8 @@
+*   Fixed serialized fields returning serialized data after being updated with
+    `update_column`.
+
+    *Simon Hørup Eskildsen*
+
 *   Fixed polymorphic eager loading when using a String as foreign key.
 
     Fixes #14734.
diff --git a/activerecord/lib/active_record/attribute_methods/serialization.rb b/activerecord/lib/active_record/attribute_methods/serialization.rb
index c3466153d6..53a9c874bf 100644
--- a/activerecord/lib/active_record/attribute_methods/serialization.rb
+++ b/activerecord/lib/active_record/attribute_methods/serialization.rb
@@ -142,6 +142,14 @@ module ActiveRecord
           end
         end
 
+        def raw_type_cast_attribute_for_write(column, value)
+          if column && coder = self.class.serialized_attributes[column.name]
+            Attribute.new(coder, value, :serialized)
+          else
+            super
+          end
+        end
+
         def _field_changed?(attr, old, value)
           if self.class.serialized_attributes.include?(attr)
             old != value
diff --git a/activerecord/lib/active_record/attribute_methods/write.rb b/activerecord/lib/active_record/attribute_methods/write.rb
index c853fc0917..56441d7324 100644
--- a/activerecord/lib/active_record/attribute_methods/write.rb
+++ b/activerecord/lib/active_record/attribute_methods/write.rb
@@ -55,24 +55,12 @@ module ActiveRecord
       # specified +value+. Empty strings for fixnum and float columns are
       # turned into +nil+.
       def write_attribute(attr_name, value)
-        attr_name = attr_name.to_s
-        attr_name = self.class.primary_key if attr_name == 'id' && self.class.primary_key
-        @attributes_cache.delete(attr_name)
-        column = column_for_attribute(attr_name)
-
-        # If we're dealing with a binary column, write the data to the cache
-        # so we don't attempt to typecast multiple times.
-        if column && column.binary?
-          @attributes_cache[attr_name] = value
-        end
-
-        if column || @attributes.has_key?(attr_name)
-          @attributes[attr_name] = type_cast_attribute_for_write(column, value)
-        else
-          raise ActiveModel::MissingAttributeError, "can't write unknown attribute `#{attr_name}'"
-        end
+        write_attribute_with_type_cast(attr_name, value, :type_cast_attribute_for_write)
+      end
+
+      def raw_write_attribute(attr_name, value)
+        write_attribute_with_type_cast(attr_name, value, :raw_type_cast_attribute_for_write)
       end
-      alias_method :raw_write_attribute, :write_attribute
 
       private
       # Handle *= for method_missing.
@@ -85,6 +73,26 @@ module ActiveRecord
 
         column.type_cast_for_write value
       end
+      alias_method :raw_type_cast_attribute_for_write, :type_cast_attribute_for_write
+
+      def write_attribute_with_type_cast(attr_name, value, type_cast_method)
+        attr_name = attr_name.to_s
+        attr_name = self.class.primary_key if attr_name == 'id' && self.class.primary_key
+        @attributes_cache.delete(attr_name)
+        column = column_for_attribute(attr_name)
+
+        # If we're dealing with a binary column, write the data to the cache
+        # so we don't attempt to typecast multiple times.
+        if column && column.binary?
+          @attributes_cache[attr_name] = value
+        end
+
+        if column || @attributes.has_key?(attr_name)
+          @attributes[attr_name] = send(type_cast_method, column, value)
+        else
+          raise ActiveModel::MissingAttributeError, "can't write unknown attribute `#{attr_name}'"
+        end
+      end
     end
   end
 end
diff --git a/activerecord/test/cases/serialized_attribute_test.rb b/activerecord/test/cases/serialized_attribute_test.rb
index 5609cf310c..c8f9d7cf87 100644
--- a/activerecord/test/cases/serialized_attribute_test.rb
+++ b/activerecord/test/cases/serialized_attribute_test.rb
@@ -244,4 +244,20 @@ class SerializedAttributeTest < ActiveRecord::TestCase
     type = Topic.column_types["content"]
     assert !type.instance_variable_get("@column").is_a?(ActiveRecord::AttributeMethods::Serialization::Type)
   end
+
+  def test_serialized_column_should_unserialize_after_update_column
+    t = Topic.create(content: "first")
+    assert_equal("first", t.content)
+
+    t.update_column(:content, Topic.serialized_attributes["content"].dump("second"))
+    assert_equal("second", t.content)
+  end
+
+  def test_serialized_column_should_unserialize_after_update_attribute
+    t = Topic.create(content: "first")
+    assert_equal("first", t.content)
+
+    t.update_attribute(:content, "second")
+    assert_equal("second", t.content)
+  end
 end