diff --git a/browser/components/markdown.styl b/browser/components/markdown.styl
index ab6c4bc7..89bbf0ab 100644
--- a/browser/components/markdown.styl
+++ b/browser/components/markdown.styl
@@ -77,6 +77,9 @@ body
 li
   label.taskListItem
     margin-left -2em
+    &.checked
+      text-decoration line-through
+      opacity 0.5
 div.math-rendered
   text-align center
 .math-failed
diff --git a/browser/lib/markdown.js b/browser/lib/markdown.js
index 60d6d0bf..da1330cc 100644
--- a/browser/lib/markdown.js
+++ b/browser/lib/markdown.js
@@ -115,7 +115,7 @@ md.block.ruler.at('paragraph', function (state, startLine/*, endLine */) {
   if (state.parentType === 'list') {
     const match = content.match(/^\[( |x)\] ?(.+)/i)
     if (match) {
-      content = `<label class='taskListItem' for='checkbox-${startLine + 1}'><input type='checkbox'${match[1] !== ' ' ? ' checked' : ''} id='checkbox-${startLine + 1}'/> ${content.substring(4, content.length)}</label>`
+      content = `<label class='taskListItem${match[1] !== ' ' ? ' checked' : ''}' for='checkbox-${startLine + 1}'><input type='checkbox'${match[1] !== ' ' ? ' checked' : ''} id='checkbox-${startLine + 1}'/> ${content.substring(4, content.length)}</label>`
     }
   }