diff --git a/lib/really_simple_captcha/captcha/plain_captcha.rb b/lib/really_simple_captcha/captcha/plain_captcha.rb
index 25a7c52..1efc44f 100644
--- a/lib/really_simple_captcha/captcha/plain_captcha.rb
+++ b/lib/really_simple_captcha/captcha/plain_captcha.rb
@@ -44,7 +44,7 @@ module ReallySimpleCaptcha::Captcha
 
         content_tag :div, class: 'plain_captcha' do
           html = image_tag "data:image/gif;base64,#{image}", alt: "Captcha"
-          html.concat text_field_tag PlainCaptcha.field_name, nil, required: 'required', autocomplete: 'off'
+          html.concat text_field_tag PlainCaptcha.field_name, nil, id: "reverse_captcha_#{Time.now.nsec}", required: 'required', autocomplete: 'off'
 
           html
         end
diff --git a/lib/really_simple_captcha/captcha/reverse_captcha.rb b/lib/really_simple_captcha/captcha/reverse_captcha.rb
index bd354fd..b3945c8 100644
--- a/lib/really_simple_captcha/captcha/reverse_captcha.rb
+++ b/lib/really_simple_captcha/captcha/reverse_captcha.rb
@@ -11,7 +11,7 @@ module ReallySimpleCaptcha::Captcha
 
     module ViewHelpers
       def reverse_captcha_tag
-        content_tag :div, text_field_tag(ReverseCaptcha.field_name), class: 'reverse_captcha', style: 'display: none'
+        content_tag :div, text_field_tag(ReverseCaptcha.field_name, nil, id: "reverse_captcha_#{Time.now.nsec}"), class: 'reverse_captcha', style: 'display: none'
       end
     end