diff --git a/config.rb b/config.rb
index adb370224..88bc5c4b4 100644
--- a/config.rb
+++ b/config.rb
@@ -104,7 +104,7 @@ def primary_page_class
   def asciinema_video(id, speed: 1)
     <<-HTML.gsub(/^ +\|/, '')
       |<div class="asciinema-video">
-      |  <script type="text/javascript" src="https://asciinema.org/a/#{id}.js" id="asciicast-#{id}" data-size="small" data-speed="#{speed}", async></script>
+      |  <script type="text/javascript" src="https://asciinema.org/a/#{id}.js" id="asciicast-#{id}" data-size="small" data-speed="#{speed}" async></script>
       |</div>
     HTML
   end