diff --git a/js/generic.js b/js/generic.js
index 5c46c0d7..2cab1885 100644
--- a/js/generic.js
+++ b/js/generic.js
@@ -397,7 +397,7 @@ const get_isVer = () => new Promise(resolve => {
 		}
 		isVer = verNo
 		if (verNo < 102) {isVerExtra = " or lower"
-		} else if (verNo == 119) {isVerExtra = "+"}
+		} else if (verNo == 120) {isVerExtra = "+"}
 		log_perf(SECTG, "isVer", t0, "", isVer + isVerExtra)
 		return resolve()
 	}
@@ -405,6 +405,7 @@ const get_isVer = () => new Promise(resolve => {
 
 	function cascade() {
 		try {
+			if ("function" === typeof CSSPropertyRule) return 120 // 1854937
 			try {location.href = "http://a>b/"} catch(e) {if (e.name === "SyntaxError") return 119} // 1817591
 			if (CSS2Properties.prototype.hasOwnProperty("fontSynthesisPosition")) return 118 // 1849010
 			if (CanvasRenderingContext2D.prototype.hasOwnProperty("fontStretch")) return 117 // 1842467
diff --git a/tests/testgeneric.js b/tests/testgeneric.js
index cd734a53..83445462 100644
--- a/tests/testgeneric.js
+++ b/tests/testgeneric.js
@@ -338,8 +338,12 @@ const get_isTB = () => new Promise(resolve => {
 		// extensions can block resources://
 			// FF ~5ms, TB ~20ms
 		setTimeout(() => resolve(false), 100)
+
+		let source = "resource://torbutton-assets/aboutTor.css"
+		// ToDo: TB13+: does not work on android
+		if (CanvasRenderingContext2D.prototype.hasOwnProperty("letterSpacing")) {source = "chrome://browser/content/abouttor/aboutTor.css"} // FF115+
 		let css = document.createElement("link")
-		css.href = "resource://torbutton-assets/aboutTor.css"
+		css.href = source
 		css.type = "text/css"
 		css.rel = "stylesheet"
 		document.head.appendChild(css)
@@ -379,7 +383,8 @@ const get_isVer = () => new Promise(resolve => {
 	output(cascade())
 
 	function cascade() {
-		isVerMax = 119
+		isVerMax = 120
+		if ("function" === typeof CSSPropertyRule) return 120 // 1854937
 		try {location.href = "http://a>b/"} catch(e) {if (e.name === "SyntaxError") return 119} // 1817591
 		if ("function" === typeof CSS2Properties && CSS2Properties.prototype.hasOwnProperty("fontSynthesisPosition")) return 118 // 1849010
 		if (CanvasRenderingContext2D.prototype.hasOwnProperty("fontStretch")) return 117 // 1842467
diff --git a/tests/versions.html b/tests/versions.html
index a598c5c7..6c779e91 100644
--- a/tests/versions.html
+++ b/tests/versions.html
@@ -208,7 +208,7 @@
 		if (debug.length) {dom.debug.innerHTML = debug.join("<br>")}
 	}
 
-	let countTZP = 0, expectTZP = 70, maxVer = 119, oTZP = {}, oResults = {}
+	let countTZP = 0, expectTZP = 71, maxVer = 120, oTZP = {}, oResults = {}
 	function run_tzp() {
 		// start global timer
 		gTZP = performance.now()
@@ -277,12 +277,16 @@
 			offsetPosition : layout.css.motion-path-offset-position.enabled
 		*/
 
+		// 120: 1854937
+		let t120 = performance.now()
+		let ver120 = ("function" === typeof CSSPropertyRule)
+		rec(120, 120, "1854937", ver120, performance.now()-t120)
+
 		// 119: 1817591
 		let t119 = performance.now()
 		try {
 			location.href = "http://a>b/"
 		} catch(e) {
-			debug.push("119 1817591 : "+ e.name)
 			rec(119, 119, "1817591", e.name === "SyntaxError", performance.now()-t119)
 		}