diff --git a/files/en-us/web/svg/element/mask/index.md b/files/en-us/web/svg/element/mask/index.md
index 7892c53b7e9f7cb..d0bc99242065a6f 100644
--- a/files/en-us/web/svg/element/mask/index.md
+++ b/files/en-us/web/svg/element/mask/index.md
@@ -21,6 +21,7 @@ svg {
 
 ```html
 <svg viewBox="-10 -10 120 120">
+<rect x="-10" y="-10" width="120" height="120" fill="blue"/>
   <mask id="myMask">
     <!-- Everything under a white pixel will be visible -->
     <rect x="0" y="0" width="100" height="100" fill="white" />
@@ -34,7 +35,7 @@ svg {
   <polygon points="-10,110 110,110 110,-10" fill="orange" />
 
   <!-- with this mask applied, we "punch" a heart shape hole into the circle -->
-  <circle cx="50" cy="50" r="50" mask="url(#myMask)" />
+  <circle cx="50" cy="50" r="50" fill="purple" mask="url(#myMask)" />
 </svg>
 ```