diff --git a/.vscode/settings.json b/.vscode/settings.json
index 895cec7..047b845 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -27,6 +27,7 @@
 		"fakeable",
 		"fragmenter",
 		"graytext",
+		"iframe",
 		"ignorelist",
 		"micrococo",
 		"monero",
@@ -39,6 +40,8 @@
 		"unticking",
 		"webgl",
 		"whitelisted",
+		"writeln",
+		"wyciwyg",
 		"yfdyh"
 	],
 	"cSpell.language": "en,de,en-GB"
diff --git a/lib/iframeProtection.js b/lib/iframeProtection.js
index 62ff30f..996acea 100644
--- a/lib/iframeProtection.js
+++ b/lib/iframeProtection.js
@@ -148,7 +148,12 @@
 		);
 		const documentWrite = documentWriteDescriptor.value;
 		documentWriteDescriptor.value = exportFunction(function write(str){
-			const parts = str.split(/(?=<)/);
+			str = "" + str;
+			// weird problem with waterfox and google docs
+			const parts = (
+				str.match(/^\s*<!doctype/i) &&
+				!str.match(/frame/i)
+			)? [str]: str.split(/(?=<)/);
 			const length = parts.length;
 			const scripts = window.document.getElementsByTagName("script");
 			for (let i = 0; i < length; i += 1){
@@ -170,6 +175,7 @@
 		);
 		const documentWriteln = documentWritelnDescriptor.value;
 		documentWritelnDescriptor.value = exportFunction(function writeln(str){
+			str = "" + str;
 			const parts = str.split(/(?=<)/);
 			const length = parts.length - 1;
 			const scripts = window.document.getElementsByTagName("script");
diff --git a/releaseNotes.txt b/releaseNotes.txt
index 4e1c429..7adb27f 100644
--- a/releaseNotes.txt
+++ b/releaseNotes.txt
@@ -8,8 +8,10 @@ Version 0.5.10:
 	
 	fixes:
 		- setter for innerHTML broke pages
-		- protection for document.write and document.wirteln broke in Firefox 69
+		- protection for document.write and document.writeln broke in Firefox 69
 		- not connected iFrame threw error with persistent rng
+		- detection over document.write and document.writeln was possible
+		- google docs were broken in Waterfox
 	
 	known issues:
 		- if a data URL is blocked the page action button does not appear
diff --git a/test/iframeTest.html b/test/iframeTest.html
index 7d01d9d..208de86 100644
--- a/test/iframeTest.html
+++ b/test/iframeTest.html
@@ -24,9 +24,18 @@
 		});
 		document.writeln("<iframe></iframe><script>log(\"TEST:\", \"iframe and script in document.writeln:\", compare(test(window[4]), reference));<\/script>");
 		document.write("<script src=\"iframeTest.js\"><\/script><iframe></iframe><script>log(\"TEST:\", \"script with src, iframe and script in document.write:\", compare(test(window[5]), reference));<\/script>");
+		
+		"<ifr|ame></ifr|ame>".split("|").forEach(function(part){
+			document.write(part);
+		});
+		document.write("<script>log(\"TEST:\", \"ifr|ame split:\", compare(test(window[6]), reference));<\/script>");
 		window.addEventListener("load", function(){
 			// document.open();
-			document.write("<script src=\"iframeTest.js\"><\/script><iframe></iframe><script>log(\"TEST:\", \"reopened document: script with src, iframe and script in document.write:\", compare(test(window[0]), reference, true));<\/script>");
+			"<ifr|ame></ifr|ame>".split("|").forEach(function(part){
+				document.write(part);
+			});
+			document.write("<script>log(\"TEST:\", \"reopened document: ifr|ame split:\", compare(test(window[0]), reference));<\/script>");
+			document.write("<script src=\"iframeTest.js\"><\/script><iframe></iframe><script>log(\"TEST:\", \"reopened document: script with src, iframe and script in document.write:\", compare(test(window[1]), reference, true));<\/script>");
 			// document.close();
 		});
 		window.setTimeout(function(){