diff --git a/app/controllers/file_controller.rb b/app/controllers/file_controller.rb
index 76639788..c6eb66d6 100644
--- a/app/controllers/file_controller.rb
+++ b/app/controllers/file_controller.rb
@@ -24,10 +24,21 @@ def show
       ip: request.remote_ip
     )
 
-    send_file current_file.path, filename: current_file.file_name, disposition:
+    send_file current_file.path, filename: current_file.file_name, type: file_type, disposition:
   end
   # rubocop:enable Metrics/AbcSize
 
+  def file_type
+    mimetype = current_file.cocina.find_file(current_file.file_name)['hasMimeType']
+    return mimetype unless mimetype.starts_with?('text')
+
+    content = File.read(current_file.path)
+    encoding = content.encoding.name
+    mimetype += "; charset=#{encoding}"
+
+    mimetype
+  end
+
   def options
     response.headers['Access-Control-Allow-Methods'] = 'GET, OPTIONS'
     response.headers['Access-Control-Allow-Headers'] = 'Range'