diff --git a/tool/block_cloudflare_requests_pm/src/header.js b/tool/block_cloudflare_requests_pm/src/header.js
new file mode 100644
index 000000000..3bd0371a5
--- /dev/null
+++ b/tool/block_cloudflare_requests_pm/src/header.js
@@ -0,0 +1,35 @@
+const Cc = Components.classes,
+	Ci = Components.interfaces;
+function ignoreCF(h) {
+	return /(cloudflare(\-(dns|free|ipfs|quic)|(support|warp)))\.com$/.test(h) ? true : false;
+}
+let knownCF = [];
+let CFBlocking = {
+	observe: function (subject, topic, data) {
+		let httpChl = subject.QueryInterface(Ci.nsIHttpChannel),
+			reqURL = subject.URI.spec;
+		if (reqURL.indexOf('http') === 0 && reqURL.indexOf('.archive.org/') === -1) {
+			let hostN = (new URL(reqURL)).hostname;
+			if (topic == 'http-on-modify-request') {
+				if (knownCF.includes(hostN)) {
+					httpChl.cancel(Cr.NS_BINDING_ABORTED);
+				}
+			}
+			if (topic == 'http-on-examine-response') {
+				let rayid = '';
+				try {
+					rayid = httpChl.getResponseHeader('cf-ray');
+				} catch (e) {}
+				if (rayid.length > 3) {
+					if (!knownCF.includes(hostN) && !ignoreCF(hostN)) {
+						knownCF.push(hostN);
+					}
+					httpChl.cancel(Cr.NS_BINDING_ABORTED);
+				}
+			}
+		}
+	}
+};
+let OBS = Cc['@mozilla.org/observer-service;1'].getService(Ci.nsIObserverService);
+OBS.addObserver(CFBlocking, 'http-on-modify-request', false);
+OBS.addObserver(CFBlocking, 'http-on-examine-response', false);
\ No newline at end of file
diff --git a/tool/block_cloudflare_requests_pm/src/header.xul b/tool/block_cloudflare_requests_pm/src/header.xul
new file mode 100644
index 000000000..cb78e57c9
--- /dev/null
+++ b/tool/block_cloudflare_requests_pm/src/header.xul
@@ -0,0 +1,4 @@
+<?xml version="1.0"?>
+<overlay xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">
+   <script type="application/x-javascript" src="chrome://cfblocker/content/header.js"></script>
+</overlay>
\ No newline at end of file