diff --git a/lib/core/GraphicsFactory.js b/lib/core/GraphicsFactory.js
index 5875570dd..3b8b9dbab 100644
--- a/lib/core/GraphicsFactory.js
+++ b/lib/core/GraphicsFactory.js
@@ -222,5 +222,7 @@ GraphicsFactory.prototype.remove = function(element) {
 // helpers //////////////////////
 
 function prependTo(newNode, parentNode, siblingNode) {
-  parentNode.insertBefore(newNode, siblingNode || parentNode.firstChild);
+  // must ensure second argument is node or _null_
+  // cf. https://developer.mozilla.org/en-US/docs/Web/API/Node/insertBefore
+  parentNode.insertBefore(newNode, siblingNode || parentNode.firstChild || null);
 }
diff --git a/lib/features/overlays/Overlays.js b/lib/features/overlays/Overlays.js
index 551b595ff..3cb923fa9 100644
--- a/lib/features/overlays/Overlays.js
+++ b/lib/features/overlays/Overlays.js
@@ -617,9 +617,14 @@ Overlays.prototype._init = function() {
 
 // helpers /////////////////////////////
 
-function createRoot(parent) {
-  var root = domify('<div class="djs-overlay-container" style="position: absolute; width: 0; height: 0;" />');
-  parent.insertBefore(root, parent.firstChild);
+function createRoot(parentNode) {
+  var root = domify(
+    '<div class="djs-overlay-container" style="position: absolute; width: 0; height: 0;" />'
+  );
+
+  // must ensure second argument is node or _null_
+  // cf. https://developer.mozilla.org/en-US/docs/Web/API/Node/insertBefore
+  parentNode.insertBefore(root, parentNode.firstChild || null);
 
   return root;
 }
diff --git a/lib/features/tooltips/Tooltips.js b/lib/features/tooltips/Tooltips.js
index 08f2f9b67..aab780a52 100644
--- a/lib/features/tooltips/Tooltips.js
+++ b/lib/features/tooltips/Tooltips.js
@@ -18,9 +18,15 @@ import Ids from '../../util/IdGenerator';
 var ids = new Ids('tt');
 
 
-function createRoot(parent) {
-  var root = domify('<div class="djs-tooltip-container" style="position: absolute; width: 0; height: 0;" />');
-  parent.insertBefore(root, parent.firstChild);
+function createRoot(parentNode) {
+  var root = domify(
+    '<div class="djs-tooltip-container" style="position: absolute; width: 0; height: 0;" />'
+  );
+
+  // must ensure second argument is node or _null_
+  // cf. https://developer.mozilla.org/en-US/docs/Web/API/Node/insertBefore
+  parentNode.insertBefore(root, parentNode.firstChild || null);
+
 
   return root;
 }