diff --git a/layouts/shortcodes/collapse.html b/layouts/shortcodes/collapse.html
index 17d8d3b..1c5e96f 100644
--- a/layouts/shortcodes/collapse.html
+++ b/layouts/shortcodes/collapse.html
@@ -1,8 +1,4 @@
-{{ if .Get "summary" }}
-{{ else }}
-{{ warnf "missing value for param 'summary': %s" .Position }}
-{{ end }}
 <p><details {{ if (eq (.Get "openByDefault") true) }} open=true {{ end }}>
-  <summary markdown="span">{{ .Get "summary" | markdownify }}</summary>
+  <summary markdown="span">{{ .Get 0 | markdownify }}</summary>
   {{ .Inner | markdownify }}
 </details></p>