diff --git a/src/index.js b/src/index.js
index 69b7d7abf..b951563ad 100755
--- a/src/index.js
+++ b/src/index.js
@@ -189,6 +189,7 @@ class ReactTooltip extends React.Component {
     let domRoot;
 
     switch (parentNode.constructor.name) {
+      case 'Document':
       case 'HTMLDocument':
         domRoot = parentNode.head;
         break;