diff --git a/lib/middleman-imageoptim/manifest_resource.rb b/lib/middleman-imageoptim/manifest_resource.rb
index 0e462d0..cd3e2f4 100644
--- a/lib/middleman-imageoptim/manifest_resource.rb
+++ b/lib/middleman-imageoptim/manifest_resource.rb
@@ -29,10 +29,11 @@ def ignored?
       private
 
       def manifest_content
-        if @source_file.nil?
+        path = File.join(@app.config[:build_dir], @destination_path)
+        if !File.exist?(path)
           YAML.dump({})
         else
-          File.read(@source_file)
+          File.read(path)
         end
       end
     end
diff --git a/lib/middleman-imageoptim/optimizer.rb b/lib/middleman-imageoptim/optimizer.rb
index cda579d..9ea0fac 100644
--- a/lib/middleman-imageoptim/optimizer.rb
+++ b/lib/middleman-imageoptim/optimizer.rb
@@ -43,7 +43,8 @@ def process_image(source, destination = nil, mode = nil)
           say_status '%{source} (%{percent_change} / %{size_change} %{size_change_type})', Utils.file_size_stats(source, destination)
           FileUtils.move(destination, source)
         else
-          say_status '[skipped] %{source} not updated', source: source
+          skip_message = '[skipped] %{source} - optimized version is identical to source (may have been previously optimized)'
+          say_status skip_message, source: source
         end
       ensure
         ensure_file_mode(mode, source) unless mode.nil?