diff --git a/mithril.js b/mithril.js
index 1946fd77..569b3c70 100644
--- a/mithril.js
+++ b/mithril.js
@@ -118,7 +118,7 @@ Mithril = m = new function app(window, undefined) {
 							if (!existing[key]) existing[key] = {action: INSERTION, index: i}
 							else existing[key] = {action: MOVE, index: i, from: existing[key].index, element: parentElement.childNodes[existing[key].index]}
 						}
-						else unkeyed.push({index: i, element: parentElement.childNodes[i]})
+						else unkeyed.push({index: i, element: parentElement.childNodes[i] || window.document.createElement("dummy")})
 					}
 				}
 				var actions = Object.keys(existing).map(function(key) {return existing[key]})
@@ -131,7 +131,7 @@ Mithril = m = new function app(window, undefined) {
 						newCached.splice(change.index, 1)
 					}
 					if (change.action == INSERTION) {
-						var dummy = window.document.createElement("div")
+						var dummy = window.document.createElement("dummy2")
 						dummy.key = data[change.index].attrs.key
 						parentElement.insertBefore(dummy, parentElement.childNodes[change.index])
 						newCached.splice(change.index, 0, {attrs: {key: data[change.index].attrs.key}, nodes: [dummy]})
diff --git a/tests/mithril-tests.js b/tests/mithril-tests.js
index 3159b8bb..e70e1bdc 100644
--- a/tests/mithril-tests.js
+++ b/tests/mithril-tests.js
@@ -584,6 +584,17 @@ function testMithril(mock) {
 		var fifthAfter = root.childNodes[1]
 		return firstBefore === firstAfter && secondBefore === secondAfter && thirdBefore === thirdAfter && fourthBefore === fourthAfter && fifthBefore === fifthAfter
 	})
+	test(function() {
+		//https://github.com/lhorie/mithril.js/issues/246
+		//insert at beginning with non-keyed in the middle
+		var root = mock.document.createElement("div")
+		m.render(root, [m("a", {key: 1})])
+		var firstBefore = root.childNodes[0]
+		m.render(root, [m("a", {key: 2}), m("br"), m("a", {key: 1})])
+		var firstAfter = root.childNodes[2]
+		console.log(root.childNodes)
+		return firstBefore == firstAfter && root.childNodes[0].key == 2 && root.childNodes.length == 3
+	})
 	test(function() {
 		//https://github.com/lhorie/mithril.js/issues/134
 		var root = mock.document.createElement("div")
diff --git a/tests/mock.js b/tests/mock.js
index fae3574e..660f08f4 100644
--- a/tests/mock.js
+++ b/tests/mock.js
@@ -15,7 +15,11 @@ mock.window = new function() {
 			insertBefore: function(node, reference) {
 				node.parentNode = this
 				var referenceIndex = this.childNodes.indexOf(reference)
-				if (referenceIndex < 0) this.childNodes.push(node)
+				if (referenceIndex < 0) {
+					var index = this.childNodes.indexOf(node)
+					if (index > -1) this.childNodes.splice(index, 1) 
+					this.childNodes.push(node)
+				}
 				else {
 					var index = this.childNodes.indexOf(node)
 					if (index > -1) this.childNodes.splice(index, 1)