diff --git a/src/js/resources/scriptlets.js b/src/js/resources/scriptlets.js
index ba196f85a..ab77be711 100755
--- a/src/js/resources/scriptlets.js
+++ b/src/js/resources/scriptlets.js
@@ -2686,7 +2686,16 @@ function trustedPreventDomBypass(
                     }
                 }
                 if ( targetProp !== '' ) {
-                    elem.contentWindow[targetProp] = self[targetProp];
+                    let me = self, it = elem.contentWindow;
+                    let chain = targetProp;
+                    for (;;) {
+                        const pos = chain.indexOf('.');
+                        if ( pos === -1 ) { break; }
+                        const prop = chain.slice(0, pos)
+                        me = me[prop]; it = it[prop];
+                        chain = chain.slice(pos+1);
+                    }
+                    it[chain] = me[chain];
                 } else {
                     Object.defineProperty(elem, 'contentWindow', { value: self });
                 }