diff --git a/render/render.js b/render/render.js
index 53031380..a9539671 100644
--- a/render/render.js
+++ b/render/render.js
@@ -5,9 +5,7 @@ var df = require("../render/domFor")
 var delayedRemoval = df.delayedRemoval
 var domFor = df.domFor
 
-module.exports = function($window) {
-	var $doc = $window && $window.document
-
+module.exports = function() {
 	var nameSpace = {
 		svg: "http://www.w3.org/2000/svg",
 		math: "http://www.w3.org/1998/Math/MathML"
@@ -16,6 +14,10 @@ module.exports = function($window) {
 	var currentRedraw
 	var currentRender
 
+	function getDocument(dom) {
+		return dom.ownerDocument;
+	}
+
 	function getNameSpace(vnode) {
 		return vnode.attrs && vnode.attrs.xmlns || nameSpace[vnode.tag]
 	}
@@ -40,9 +42,9 @@ module.exports = function($window) {
 
 	// IE11 (at least) throws an UnspecifiedError when accessing document.activeElement when
 	// inside an iframe. Catch and swallow this error, and heavy-handidly return null.
-	function activeElement() {
+	function activeElement(dom) {
 		try {
-			return $doc.activeElement
+			return getDocument(dom).activeElement
 		} catch (e) {
 			return null
 		}
@@ -71,7 +73,7 @@ module.exports = function($window) {
 		else createComponent(parent, vnode, hooks, ns, nextSibling)
 	}
 	function createText(parent, vnode, nextSibling) {
-		vnode.dom = $doc.createTextNode(vnode.children)
+		vnode.dom = getDocument(parent).createTextNode(vnode.children)
 		insertDOM(parent, vnode.dom, nextSibling)
 	}
 	var possibleParents = {caption: "table", thead: "table", tbody: "table", tfoot: "table", tr: "tbody", th: "tr", td: "tr", colgroup: "table", col: "colgroup"}
@@ -82,7 +84,7 @@ module.exports = function($window) {
 		//     div.innerHTML = "<td>i</td><td>j</td>"
 		//     console.log(div.innerHTML)
 		// --> "ij", no <td> in sight.
-		var temp = $doc.createElement(possibleParents[match[1]] || "div")
+		var temp = getDocument(parent).createElement(possibleParents[match[1]] || "div")
 		if (ns === "http://www.w3.org/2000/svg") {
 			temp.innerHTML = "<svg xmlns=\"http://www.w3.org/2000/svg\">" + vnode.children + "</svg>"
 			temp = temp.firstChild
@@ -92,7 +94,7 @@ module.exports = function($window) {
 		vnode.dom = temp.firstChild
 		vnode.domSize = temp.childNodes.length
 		// Capture nodes to remove, so we don't confuse them.
-		var fragment = $doc.createDocumentFragment()
+		var fragment = getDocument(parent).createDocumentFragment()
 		var child
 		while (child = temp.firstChild) {
 			fragment.appendChild(child)
@@ -100,7 +102,7 @@ module.exports = function($window) {
 		insertDOM(parent, fragment, nextSibling)
 	}
 	function createFragment(parent, vnode, hooks, ns, nextSibling) {
-		var fragment = $doc.createDocumentFragment()
+		var fragment = getDocument(parent).createDocumentFragment()
 		if (vnode.children != null) {
 			var children = vnode.children
 			createNodes(fragment, children, 0, children.length, hooks, null, ns)
@@ -117,8 +119,8 @@ module.exports = function($window) {
 		ns = getNameSpace(vnode) || ns
 
 		var element = ns ?
-			is ? $doc.createElementNS(ns, tag, {is: is}) : $doc.createElementNS(ns, tag) :
-			is ? $doc.createElement(tag, {is: is}) : $doc.createElement(tag)
+			is ? getDocument(parent).createElementNS(ns, tag, {is: is}) : getDocument(parent).createElementNS(ns, tag) :
+			is ? getDocument(parent).createElement(tag, {is: is}) : getDocument(parent).createElement(tag)
 		vnode.dom = element
 
 		if (attrs != null) {
@@ -553,7 +555,7 @@ module.exports = function($window) {
 				// don't allocate for the common case
 				target = vnode.dom
 			} else {
-				target = $doc.createDocumentFragment()
+				target = getDocument(parent).createDocumentFragment()
 				for (var dom of domFor(vnode)) target.appendChild(dom)
 			}
 			insertDOM(parent, target, nextSibling)
@@ -693,7 +695,7 @@ module.exports = function($window) {
 				/* eslint-disable no-implicit-coercion */
 				//setting input[value] to same value by typing on focused element moves cursor to end in Chrome
 				//setting input[type=file][value] to same value causes an error to be generated if it's non-empty
-				if ((vnode.tag === "input" || vnode.tag === "textarea") && vnode.dom.value === "" + value && (isFileInput || vnode.dom === activeElement())) return
+				if ((vnode.tag === "input" || vnode.tag === "textarea") && vnode.dom.value === "" + value && (isFileInput || vnode.dom === activeElement(vnode.dom))) return
 				//setting select[value] to same value while having select open blinks select dropdown in Chrome
 				if (vnode.tag === "select" && old !== null && vnode.dom.value === "" + value) return
 				//setting option[value] to same value while having select open blinks select dropdown in Chrome
@@ -722,7 +724,7 @@ module.exports = function($window) {
 			&& key !== "title" // creates "null" as title
 			&& !(key === "value" && (
 				vnode.tag === "option"
-				|| vnode.tag === "select" && vnode.dom.selectedIndex === -1 && vnode.dom === activeElement()
+				|| vnode.tag === "select" && vnode.dom.selectedIndex === -1 && vnode.dom === activeElement(vnode.dom)
 			))
 			&& !(vnode.tag === "input" && key === "type")
 		) {
@@ -771,7 +773,7 @@ module.exports = function($window) {
 		}
 	}
 	function isFormAttribute(vnode, attr) {
-		return attr === "value" || attr === "checked" || attr === "selectedIndex" || attr === "selected" && vnode.dom === activeElement() || vnode.tag === "option" && vnode.dom.parentNode === $doc.activeElement
+		return attr === "value" || attr === "checked" || attr === "selectedIndex" || attr === "selected" && vnode.dom === activeElement(vnode.dom) || vnode.tag === "option" && vnode.dom.parentNode === activeElement(vnode.dom)
 	}
 	function isLifecycleMethod(attr) {
 		return attr === "oninit" || attr === "oncreate" || attr === "onupdate" || attr === "onremove" || attr === "onbeforeremove" || attr === "onbeforeupdate"
@@ -923,7 +925,7 @@ module.exports = function($window) {
 		var prevRedraw = currentRedraw
 		var prevDOM = currentDOM
 		var hooks = []
-		var active = activeElement()
+		var active = activeElement(dom)
 		var namespace = dom.namespaceURI
 
 		currentDOM = dom
@@ -936,7 +938,7 @@ module.exports = function($window) {
 			updateNodes(dom, dom.vnodes, vnodes, hooks, null, namespace === "http://www.w3.org/1999/xhtml" ? undefined : namespace)
 			dom.vnodes = vnodes
 			// `document.activeElement` can return null: https://html.spec.whatwg.org/multipage/interaction.html#dom-document-activeelement
-			if (active != null && activeElement() !== active && typeof active.focus === "function") active.focus()
+			if (active != null && activeElement(dom) !== active && typeof active.focus === "function") active.focus()
 			for (var i = 0; i < hooks.length; i++) hooks[i]()
 		} finally {
 			currentRedraw = prevRedraw
diff --git a/test-utils/domMock.js b/test-utils/domMock.js
index 883b2cb1..5536b49f 100644
--- a/test-utils/domMock.js
+++ b/test-utils/domMock.js
@@ -307,6 +307,7 @@ module.exports = function(options) {
 					parentNode: null,
 					childNodes: [],
 					attributes: {},
+					ownerDocument: $window.document,
 					contains: function(child) {
 						while (child != null) {
 							if (child === this) return true
@@ -717,6 +718,7 @@ module.exports = function(options) {
 			},
 			createDocumentFragment: function() {
 				return {
+					ownerDocument: $window.document,
 					nodeType: 11,
 					nodeName: "#document-fragment",
 					appendChild: appendChild,
@@ -738,6 +740,7 @@ module.exports = function(options) {
 			get activeElement() {return activeElement},
 		},
 	}
+	$window.document.defaultView = $window
 	$window.document.documentElement = $window.document.createElement("html")
 	appendChild.call($window.document.documentElement, $window.document.createElement("head"))
 	$window.document.body = $window.document.createElement("body")