diff --git a/extract_thumbs.rb b/extract_thumbs.rb
index df24980..85afcd0 100644
--- a/extract_thumbs.rb
+++ b/extract_thumbs.rb
@@ -14,6 +14,10 @@
   Zip::File.open(f) do |zipfile|
     file_name = zipfile.name.split('/').last.split('.').first.split('-').first
     thumbnail = zipfile.find { |v| v.name.start_with? 'docProps/thumbnail' }
+    if !thumbnail
+      puts "error with #{file_name}"
+      next
+    end
     FileUtils.rm("#{File.expand_path File.dirname(__FILE__)}/assets/thumbnails/#{file_name}.jpeg", force: true)
     thumbnail.extract("#{File.expand_path File.dirname(__FILE__)}/assets/thumbnails/#{file_name}.jpeg")
   end