diff --git a/mithril.js b/mithril.js
index f152aac4..b22a25af 100644
--- a/mithril.js
+++ b/mithril.js
@@ -261,7 +261,7 @@ var m = (function app(window, undefined) {
 			var dataAttrKeys = Object.keys(data.attrs)
 			var hasKeys = dataAttrKeys.length > ("key" in data.attrs ? 1 : 0)
 			//if an element is different enough from the one in cache, recreate it
-			if (data.tag != cached.tag || dataAttrKeys.sort().join() != Object.keys(cached.attrs).sort().join() || data.attrs.id != cached.attrs.id || data.attrs.key != cached.attrs.key || (m.redraw.strategy() == "all" && cached.configContext && cached.configContext.retain !== true) || (m.redraw.strategy() == "diff" && cached.configContext && cached.configContext.retain === false)) {
+			if (data.tag != cached.tag || dataAttrKeys.sort().join() != Object.keys(cached.attrs).sort().join() || data.attrs.id != cached.attrs.id || data.attrs.key != cached.attrs.key || (m.redraw.strategy() == "all" && (!cached.configContext || cached.configContext.retain !== true)) || (m.redraw.strategy() == "diff" && cached.configContext && cached.configContext.retain === false)) {
 				if (cached.nodes.length) clear(cached.nodes);
 				if (cached.configContext && typeof cached.configContext.onunload === FUNCTION) cached.configContext.onunload()
 				if (cached.controllers) {