diff --git a/theme/boost/scss/moodle/forms.scss b/theme/boost/scss/moodle/forms.scss
index 86642a92a9e..ac74684f8bc 100644
--- a/theme/boost/scss/moodle/forms.scss
+++ b/theme/boost/scss/moodle/forms.scss
@@ -403,8 +403,8 @@ textarea[data-auto-rows] {
     background-image: $form-icon-danger;
     padding-right: ($input-padding-x * 3);
     background-repeat: no-repeat;
-    background-position: center right ($input-height / 4);
-    background-size: ($input-height / 2) ($input-height / 2);
+    background-position: center right 1rem;
+    background-size: 1.5rem;
 }
 
 // Styles for the JS file types browser provided by the "filetypes" element.