diff --git a/printThis.js b/printThis.js
index b7dc8fd..38d66fd 100644
--- a/printThis.js
+++ b/printThis.js
@@ -183,6 +183,9 @@
                 }
             }
 
+            // CSS VAR in html tag when dynamic apply e.g.  document.documentElement.style.setProperty("--foo", bar);
+            $doc.find('html').prop('style', $('html')[0].style.cssText)
+
             // copy 'root' tag classes
             var tag = opt.copyTagClasses;
             if (tag) {