diff --git a/lib/friendly_id/slugged.rb b/lib/friendly_id/slugged.rb
index ab0fc2f2b..36f34c924 100644
--- a/lib/friendly_id/slugged.rb
+++ b/lib/friendly_id/slugged.rb
@@ -86,7 +86,7 @@ def self.down
     class Person < ActiveRecord::Base
       extend FriendlyId
       friendly_id :name_and_location, use: :slugged
-      
+
       def name_and_location
         "#{name} from #{location}"
       end
@@ -248,6 +248,7 @@ def self.included(model_class)
         defaults[:sequence_separator] ||= '-'
       end
       model_class.before_validation :set_slug
+      model_class.after_validation :unset_slug_if_invalid
     end
 
     # Process the given value to make it suitable for use as a slug.
@@ -324,6 +325,14 @@ def slug_generator
     end
     private :slug_generator
 
+    def unset_slug_if_invalid
+      if errors.present? && attribute_changed?(friendly_id_config.query_field)
+        diff = changes[friendly_id_config.query_field]
+        self.slug = diff.first
+      end
+    end
+    private :unset_slug_if_invalid
+
     # This module adds the `:slug_column`, and `:sequence_separator`, and
     # `:slug_generator_class` configuration options to
     # {FriendlyId::Configuration FriendlyId::Configuration}.
diff --git a/test/slugged_test.rb b/test/slugged_test.rb
index b0d334af7..531baafa7 100644
--- a/test/slugged_test.rb
+++ b/test/slugged_test.rb
@@ -92,6 +92,47 @@ def should_generate_new_friendly_id?
     end
   end
 
+  test "should not set slug on create if unrelated validations fail" do
+    klass = Class.new model_class do
+      validates_presence_of :active
+      friendly_id :name, :use => :slugged
+
+      def self.name
+        "Journalist"
+      end
+    end
+
+    transaction do
+      instance = klass.new :name => 'foo'
+      refute instance.save
+      refute instance.valid?
+      assert_nil instance.slug
+    end
+  end
+
+  test "should not update slug on save if unrelated validations fail" do
+    klass = Class.new model_class do
+      validates_presence_of :active
+      friendly_id :name, :use => :slugged
+
+      def self.name
+        "Journalist"
+      end
+    end
+
+    transaction do
+      instance = klass.new :name => 'foo', :active => true
+      assert instance.save
+      assert instance.valid?
+      instance.name = 'foobar'
+      instance.slug = nil
+      instance.active = nil
+      refute instance.save
+      refute instance.valid?
+      assert_equal 'foo', instance.slug
+    end
+  end
+
 end
 
 class SlugGeneratorTest < TestCaseClass