diff --git a/src/bg/RequestGuard.js b/src/bg/RequestGuard.js
index 564355c..1ccab69 100644
--- a/src/bg/RequestGuard.js
+++ b/src/bg/RequestGuard.js
@@ -589,7 +589,7 @@ var RequestGuard = (() => {
       if (pending && pending.redirected && pending.redirected.url === request.url) {
         return lanRes; // don't go on stripping cookies if we're in a redirection loop
       }
-      let chainNext = r => r === ABORT ? r : TabGuard.check(request);
+      let chainNext = r => r === ABORT ? r : TabGuard.onSend(request);
       return lanRes instanceof Promise ? lanRes.then(chainNext) : chainNext(lanRes);
     },
 
@@ -688,7 +688,7 @@ var RequestGuard = (() => {
       let {requestId, url, tabId, frameId, type} = request;
       if (type === "main_frame") {
         TabStatus.initTab(tabId);
-        TabGuard.postCheck(request);
+        TabGuard.onCleanup(request);
       }
       let scriptBlocked = request.responseHeaders.some(
         h => csp.isMine(h) && csp.blocks(h.value, "script")
@@ -721,11 +721,11 @@ var RequestGuard = (() => {
           }
         }
       }
-      TabGuard.postCheck(request);
+      TabGuard.onCleanup(request);
     },
     onErrorOccurred(request) {
       pendingRequests.delete(request.requestId);
-      TabGuard.postCheck(request);
+      TabGuard.onCleanup(request);
     }
   };
   function fakeRequestFromCSP(report, request) {
diff --git a/src/bg/TabGuard.js b/src/bg/TabGuard.js
index 0b6d98a..fa42a17 100644
--- a/src/bg/TabGuard.js
+++ b/src/bg/TabGuard.js
@@ -27,6 +27,8 @@ var TabGuard = (() => {
     anonymizedTabs.delete(tab.id);
   });
 
+  const anonymizedRequests = new Set();
+
   let allowedGroups, filteredGroups;
   let forget = () => {
     allowedGroups = {};
@@ -53,10 +55,12 @@ var TabGuard = (() => {
 
   return {
     forget,
-    check(request) {
+    onSend(request) {
       const mode = ns.sync.TabGuardMode;
       if (mode === "off" || !request.incognito && mode!== "global") return;
 
+      anonymizedRequests.delete(request.id);
+
       const {tabId, type, url, originUrl} = request;
 
       if (tabId < 0) return; // no tab, no party
@@ -160,6 +164,7 @@ var TabGuard = (() => {
           requestHeaders = requestHeaders.filter(h => !AUTH_HEADERS_RX.test(h.name));
           debug("[TabGuard] Removing auth headers from %o (%o)", request, requestHeaders);
           anonymizedTabs.set(tabId, {tabDomain, otherDomains: [...otherDomains]});
+          anonymizedRequests.add(request.id);
           return {requestHeaders};
         };
 
@@ -195,12 +200,16 @@ var TabGuard = (() => {
         return mustFilter ? filterAuth() : null;
       })();
     },
-    postCheck(request) {
+    onCleanup(request) {
       let {requestId, tabId} = request;
       if (scheduledCuts.has(requestId)) {
         scheduledCuts.delete(requestId);
         TabTies.cut(tabId);
       }
+      anonymizedRequests.delete(request.id);
+    },
+    isAnonymizedRequest(requestId) {
+      return anonymizedRequests.has(requestId);
     },
     isAnonymizedTab(tabId) {
       return anonymizedTabs.has(tabId);