diff --git a/background.js b/background.js
index 889c715f..161b4221 100644
--- a/background.js
+++ b/background.js
@@ -1,3 +1,11 @@
+var frameIdMessageable;
+try {
+	chrome.tabs.sendMessage(0, {}, {frameId: 0}, function() {
+		var clearError = chrome.runtime.lastError;
+		frameIdMessageable = true;
+	});
+} catch(e) {}
+
 // This happens right away, sometimes so fast that the content script isn't even ready. That's
 // why the content script also asks for this stuff.
 chrome.webNavigation.onCommitted.addListener(webNavigationListener.bind(this, "styleApply"));
@@ -7,15 +15,18 @@ function webNavigationListener(method, data) {
 	// Until Chrome 41, we can't target a frame with a message
 	// (https://developer.chrome.com/extensions/tabs#method-sendMessage)
 	// so a style affecting a page with an iframe will affect the main page as well.
-	// Skip doing this for frames for now, which can result in flicker.
-	if (data.frameId != 0) {
+	// Skip doing this for frames in pre-41 to prevent page flicker.
+	if (data.frameId != 0 && !frameIdMessageable) {
 		return;
 	}
 	getStyles({matchUrl: data.url, enabled: true, asHash: true}, function(styleHash) {
 		if (method) {
-			chrome.tabs.sendMessage(data.tabId, {method: method, styles: styleHash});
+			chrome.tabs.sendMessage(data.tabId, {method: method, styles: styleHash},
+				frameIdMessageable ? {frameId: data.frameId} : undefined);
+		}
+		if (data.frameId == 0) {
+			updateIcon({id: data.tabId, url: data.url}, styleHash);
 		}
-		updateIcon({id: data.tabId, url: data.url}, styleHash);
 	});
 }