diff --git a/css/show-full-urls-with-print-styles.md b/css/show-full-urls-with-print-styles.md
index a871f39..78d66f2 100644
--- a/css/show-full-urls-with-print-styles.md
+++ b/css/show-full-urls-with-print-styles.md
@@ -18,7 +18,7 @@ add _after content_ that renders the actual, full URL next to the link.
 ```css
 @media print 
 {
-  a[href]:after
+  a[href]::after
   {
     content: " [" attr(href) "]";
   }