diff --git a/src/js/1p-filters.js b/src/js/1p-filters.js
index 645d231d5..ccbd7067c 100644
--- a/src/js/1p-filters.js
+++ b/src/js/1p-filters.js
@@ -70,9 +70,6 @@ let cachedUserFilters = '';
         if ( response instanceof Object === false ) { return; }
         if ( response.hintUpdateToken !== undefined ) {
             const mode = cmEditor.getMode();
-            if ( typeof response.filterOnHeaders === 'boolean' ) {
-                cmEditor.setOption('filterOnHeaders', response.filterOnHeaders);
-            }
             if ( mode.setHints instanceof Function ) {
                 mode.setHints(response);
             }
diff --git a/src/js/asset-viewer.js b/src/js/asset-viewer.js
index c9d3d1cbc..060ea20a3 100644
--- a/src/js/asset-viewer.js
+++ b/src/js/asset-viewer.js
@@ -73,7 +73,6 @@ import './codemirror/ubo-static-filtering.js';
     });
     if ( hints instanceof Object ) {
         const mode = cmEditor.getMode();
-        cmEditor.setOption('filterOnHeaders', hints.filterOnHeaders === true);
         if ( mode.setHints instanceof Function ) {
             mode.setHints(hints);
         }
diff --git a/src/js/background.js b/src/js/background.js
index 0e645fa77..bcbb6f10c 100644
--- a/src/js/background.js
+++ b/src/js/background.js
@@ -71,7 +71,6 @@ const hiddenSettingsDefault = {
     disableWebAssembly: false,
     extensionUpdateForceReload: false,
     filterAuthorMode: false,
-    filterOnHeaders: false,
     loggerPopupType: 'popup',
     manualUpdateAssetFetchPeriod: 500,
     modifyWebextFlavor: 'unset',
diff --git a/src/js/benchmarks.js b/src/js/benchmarks.js
index 2354701ae..1d02dc94b 100644
--- a/src/js/benchmarks.js
+++ b/src/js/benchmarks.js
@@ -188,7 +188,7 @@ const loadBenchmarkDataset = (( ) => {
                 staticNetFilteringEngine.matchAndFetchModifiers(fctxt, 'csp');
                 staticNetFilteringEngine.matchAndFetchModifiers(fctxt, 'permissions');
             }
-            //staticNetFilteringEngine.matchHeaders(fctxt, []);
+            staticNetFilteringEngine.matchHeaders(fctxt, []);
         } else if ( redirectEngine !== undefined ) {
             staticNetFilteringEngine.redirectRequest(redirectEngine, fctxt);
         }
diff --git a/src/js/codemirror/ubo-static-filtering.js b/src/js/codemirror/ubo-static-filtering.js
index d84018b9a..963509a83 100644
--- a/src/js/codemirror/ubo-static-filtering.js
+++ b/src/js/codemirror/ubo-static-filtering.js
@@ -38,15 +38,6 @@ const originHints = [];
 let hintHelperRegistered = false;
 
 
-/******************************************************************************/
-
-let filterOnHeaders = false;
-
-CodeMirror.defineOption('filterOnHeaders', false, (cm, state) => {
-    filterOnHeaders = state;
-    self.dispatchEvent(new Event('filterOnHeaders'));
-});
-
 /******************************************************************************/
 
 CodeMirror.defineMode('ubo-static-filtering', function() {
@@ -214,10 +205,6 @@ CodeMirror.defineMode('ubo-static-filtering', function() {
         return '+';
     };
 
-    self.addEventListener('filterOnHeaders', ( ) => {
-        astParser.options.filterOnHeaders = filterOnHeaders;
-    });
-
     return {
         lineComment: '!',
         token: function(stream) {
@@ -990,10 +977,6 @@ CodeMirror.registerHelper('fold', 'ubo-static-filtering', (( ) => {
         }
     };
 
-    self.addEventListener('filterOnHeaders', ( ) => {
-        astParser.options.filterOnHeaders = filterOnHeaders;
-    });
-
     CodeMirror.defineInitHook(cm => {
         cm.on('changes', onChanges);
         cm.on('beforeChange', onBeforeChanges);
diff --git a/src/js/messaging.js b/src/js/messaging.js
index 053fad433..443b4bdfa 100644
--- a/src/js/messaging.js
+++ b/src/js/messaging.js
@@ -1600,7 +1600,6 @@ const onMessage = function(request, sender, callback) {
             response.preparseDirectiveHints =
                 sfp.utils.preparser.getHints();
             response.expertMode = µb.hiddenSettings.filterAuthorMode;
-            response.filterOnHeaders = µb.hiddenSettings.filterOnHeaders;
         }
         if ( request.hintUpdateToken !== µb.pageStoresToken ) {
             response.originHints = getOriginHints();
diff --git a/src/js/reverselookup.js b/src/js/reverselookup.js
index 757c62108..27f0136f8 100644
--- a/src/js/reverselookup.js
+++ b/src/js/reverselookup.js
@@ -131,7 +131,6 @@ const fromNetFilter = async function(rawFilter) {
     const writer = new CompiledListWriter();
     const parser = new sfp.AstFilterParser({
         expertMode: true,
-        filterOnHeaders: true,
         maxTokenLength: staticNetFilteringEngine.MAX_TOKEN_LENGTH,
         nativeCssHas: vAPI.webextFlavor.env.includes('native_css_has'),
     });
diff --git a/src/js/static-filtering-parser.js b/src/js/static-filtering-parser.js
index 4e274daea..94ee66cd1 100644
--- a/src/js/static-filtering-parser.js
+++ b/src/js/static-filtering-parser.js
@@ -1279,7 +1279,7 @@ export class AstFilterParser {
                     realBad = isException === false || isNegated || hasValue;
                     break;
                 case NODE_TYPE_NET_OPTION_NAME_HEADER:
-                    realBad = this.options.filterOnHeaders !== true || isNegated || hasValue === false;
+                    realBad = isNegated || hasValue === false;
                     break;
                 case NODE_TYPE_NET_OPTION_NAME_IMPORTANT:
                     realBad = isException || isNegated || hasValue;
diff --git a/src/js/static-net-filtering.js b/src/js/static-net-filtering.js
index fbda11573..757c5a0a8 100644
--- a/src/js/static-net-filtering.js
+++ b/src/js/static-net-filtering.js
@@ -5000,25 +5000,25 @@ FilterContainer.prototype.realmMatchString = function(
     let tokenHash = DOT_TOKEN_HASH;
     if (
         (ibucket00 !== 0) &&
-        (iunit = bucket00.get(tokenHash) || 0) !== 0 &&
+        (iunit = bucket00.get(DOT_TOKEN_HASH) || 0) !== 0 &&
         (filterMatch(iunit) === true)
     ) {
         catBits = catBits00;
     } else if (
         (ibucket01 !== 0) &&
-        (iunit = bucket01.get(tokenHash) || 0) !== 0 &&
+        (iunit = bucket01.get(DOT_TOKEN_HASH) || 0) !== 0 &&
         (filterMatch(iunit) === true)
     ) {
         catBits = catBits01;
     } else if (
         (ibucket10 !== 0) &&
-        (iunit = bucket10.get(tokenHash) || 0) !== 0 &&
+        (iunit = bucket10.get(DOT_TOKEN_HASH) || 0) !== 0 &&
         (filterMatch(iunit) === true)
     ) {
         catBits = catBits10;
     } else if (
         (ibucket11 !== 0) &&
-        (iunit = bucket11.get(tokenHash) || 0) !== 0 &&
+        (iunit = bucket11.get(DOT_TOKEN_HASH) || 0) !== 0 &&
         (filterMatch(iunit) === true)
     ) {
         catBits = catBits11;
@@ -5200,12 +5200,16 @@ FilterContainer.prototype.matchHeaders = function(fctxt, headers) {
     $httpHeaders.init(headers);
 
     let r = 0;
-    if ( this.realmMatchString(HEADERS | BlockImportant, typeBits, partyBits) ) {
+    if ( this.realmMatchString(HEADERS | BlockAction, typeBits, partyBits) ) {
         r = 1;
-    } else if ( this.realmMatchString(HEADERS | BlockAction, typeBits, partyBits) ) {
-        r = this.realmMatchString(HEADERS | AllowAction, typeBits, partyBits)
-            ? 2
-            : 1;
+    }
+    if ( r !== 0 && $isBlockImportant !== true ) {
+        if ( this.realmMatchString(HEADERS | AllowAction, typeBits, partyBits) ) {
+            r = 2;
+            if ( this.realmMatchString(HEADERS | BlockImportant, typeBits, partyBits) ) {
+                r = 1;
+            }
+        }
     }
 
     $httpHeaders.reset();
diff --git a/src/js/storage.js b/src/js/storage.js
index 7266868f4..28482e3ce 100644
--- a/src/js/storage.js
+++ b/src/js/storage.js
@@ -1051,7 +1051,6 @@ self.addEventListener('hiddenSettingsChanged', ( ) => {
         this.hiddenSettings.filterAuthorMode !== false;
     const parser = new sfp.AstFilterParser({
         expertMode,
-        filterOnHeaders: µb.hiddenSettings.filterOnHeaders,
         maxTokenLength: staticNetFilteringEngine.MAX_TOKEN_LENGTH,
         nativeCssHas: vAPI.webextFlavor.env.includes('native_css_has'),
     });
diff --git a/src/js/traffic.js b/src/js/traffic.js
index 3677cb69d..c004dbb56 100644
--- a/src/js/traffic.js
+++ b/src/js/traffic.js
@@ -516,7 +516,7 @@ const onHeadersReceived = function(details) {
     const { responseHeaders } = details;
     if ( Array.isArray(responseHeaders) === false ) { return; }
 
-    if ( isRootDoc === false && µb.hiddenSettings.filterOnHeaders === true ) {
+    if ( isRootDoc === false ) {
         const result = pageStore.filterOnHeaders(fctxt, responseHeaders);
         if ( result !== 0 ) {
             if ( logger.enabled ) {