diff --git a/lib/navigator.js b/lib/navigator.js
index 616b87d..0f48a48 100644
--- a/lib/navigator.js
+++ b/lib/navigator.js
@@ -26,6 +26,7 @@
 		original[property] = window.navigator[property];
 	});
 	original["real Firefox version"] = window.navigator.userAgent.replace(/^.+Firefox\//, "");
+	original["real Firefox version - rv"] = window.navigator.userAgent.replace(/^.+; rv:([\d.]+).*$/, "$1");
 	
 	let changedValues = {};
 	
diff --git a/options/navigator.js b/options/navigator.js
index e4bc814..d3a3f17 100644
--- a/options/navigator.js
+++ b/options/navigator.js
@@ -277,6 +277,7 @@
 			chromeVersion: "71.0.3578.98",
 			edgeVersion: "17.17134",
 			firefoxVersion: undefined,
+			firefoxVersionVR: undefined,
 			operaVersion: undefined,
 			safariVersion: undefined,
 			
@@ -293,6 +294,7 @@
 			chromeVersion: "71.0.3578.98",
 			edgeVersion: undefined,
 			firefoxVersion: undefined,
+			firefoxVersionVR: undefined,
 			operaVersion: "58.0.3135.65",
 			safariVersion: undefined,
 			
@@ -309,6 +311,7 @@
 			chromeVersion: "71.0.3578.98",
 			edgeVersion: undefined,
 			firefoxVersion: undefined,
+			firefoxVersionVR: undefined,
 			operaVersion: undefined,
 			safariVersion: undefined,
 			
@@ -325,6 +328,7 @@
 			chromeVersion: undefined,
 			edgeVersion: undefined,
 			firefoxVersion: undefined,
+			firefoxVersionVR: undefined,
 			operaVersion: undefined,
 			safariVersion: "12.0.3",
 			
@@ -341,6 +345,7 @@
 			chromeVersion: undefined,
 			edgeVersion: undefined,
 			firefoxVersion: "{real Firefox version}",
+			firefoxVersionRV: "{real Firefox version - rv}",
 			operaVersion: undefined,
 			safariVersion: undefined,
 			
@@ -350,7 +355,7 @@
 				return firefoxOscpu[currentProperties.osPreset || ""] || "{original value}";
 			},
 			productSub: "20100101",
-			userAgent: "Mozilla/5.0 ({platformDetails}; rv:{firefoxVersion}) Gecko/20100101 Firefox/{firefoxVersion}",
+			userAgent: "Mozilla/5.0 ({platformDetails}; rv:{firefoxVersionRV}) Gecko/20100101 Firefox/{firefoxVersion}",
 			vendor: undefined,
 		}
 	};
diff --git a/releaseNotes.txt b/releaseNotes.txt
index c72a513..eb6f989 100644
--- a/releaseNotes.txt
+++ b/releaseNotes.txt
@@ -5,6 +5,7 @@ Version 1.9:
 	
 	new features:
 		- added support for wildcards (*) in domains
+		- added {real Firefox version - rv} to Firefox navigator preset
 	
 	fixes:
 		- errors in URL regular expressions broke CB