diff --git a/background/style-manager.js b/background/style-manager.js
index fb58a8f7..d7d766cf 100644
--- a/background/style-manager.js
+++ b/background/style-manager.js
@@ -1,7 +1,7 @@
 /* global API msg */// msg.js
 /* global CHROME URLS deepEqual isEmptyObj mapObj stringAsRegExp tryRegExp tryURL */// toolbox.js
 /* global bgReady createCache uuidIndex */// common.js
-/* global calcStyleDigest styleCodeEmpty styleSectionGlobal */// sections-util.js
+/* global calcStyleDigest styleCodeEmpty */// sections-util.js
 /* global db */
 /* global prefs */
 /* global tabMan */
@@ -74,6 +74,29 @@ const styleMan = (() => {
     _rev: 0,
   };
   uuidIndex.addCustomId(orderWrap, {set: setOrder});
+
+  class MatchQuery {
+    constructor(url) {
+      this.url = url;
+    }
+    get urlWithoutHash() {
+      return this._set('urlWithoutHash', this.url.split('#', 1)[0]);
+    }
+    get urlWithoutParams() {
+      return this._set('urlWithoutParams', this.url.split(/[?#]/, 1)[0]);
+    }
+    get domain() {
+      return this._set('domain', tryURL(this.url).hostname);
+    }
+    get isOwnPage() {
+      return this._set('isOwnPage', this.url.startsWith(URLS.ownOrigin));
+    }
+    _set(name, value) {
+      Object.defineProperty(this, name, {value});
+      return value;
+    }
+  }
+
   /** @type {Promise|boolean} will be `true` to avoid wasting a microtask tick on each `await` */
   let ready = Promise.all([init(), prefs.ready]);
 
@@ -226,7 +249,7 @@ const styleMan = (() => {
       const styles = id
         ? [id2style(id)].filter(Boolean)
         : getAllAsArray();
-      const query = createMatchQuery(url);
+      const query = new MatchQuery(url);
       for (const style of styles) {
         let excluded = false;
         let excludedScheme = false;
@@ -248,10 +271,7 @@ const styleMan = (() => {
           excludedScheme = true;
         }
         for (const section of style.sections) {
-          if (styleSectionGlobal(section) && styleCodeEmpty(section.code)) {
-            continue;
-          }
-          const match = urlMatchSection(query, section);
+          const match = urlMatchSection(query, section, true);
           if (match) {
             if (match === 'sloppy') {
               sloppy = true;
@@ -431,7 +451,7 @@ const styleMan = (() => {
         cache.maybeMatch.add(id);
         continue;
       }
-      const code = getAppliedCode(createMatchQuery(url), style);
+      const code = getAppliedCode(new MatchQuery(url), style);
       if (code) {
         updated.add(url);
         buildCacheEntry(cache, style, code);
@@ -601,40 +621,56 @@ const styleMan = (() => {
     return true;
   }
 
-  function urlMatchSection(query, section) {
+  function urlMatchSection(query, section, skipEmptyGlobal) {
+    let dd, ddL, pp, ppL, rr, rrL, uu, uuL;
     if (
-      section.domains &&
-      section.domains.some(d => d === query.domain || query.domain.endsWith(`.${d}`))
+      (dd = section.domains) && (ddL = dd.length) && dd.some(urlMatchDomain, query) ||
+      (pp = section.urlPrefixes) && (ppL = pp.length) && pp.some(urlMatchPrefix, query) ||
+      /* Per the specification the fragment portion is ignored in @-moz-document:
+         https://www.w3.org/TR/2012/WD-css3-conditional-20120911/#url-of-doc
+         but the spec is outdated and doesn't account for SPA sites,
+         so we only respect it for `url()` function */
+      (uu = section.urls) && (uuL = uu.length) && (
+        uu.includes(query.url) ||
+        uu.includes(query.urlWithoutHash)
+      ) ||
+      (rr = section.regexps) && (rrL = rr.length) && rr.some(urlMatchRegexp, query)
     ) {
       return true;
     }
-    if (section.urlPrefixes && section.urlPrefixes.some(p => p && query.url.startsWith(p))) {
-      return true;
-    }
-    // as per spec the fragment portion is ignored in @-moz-document:
-    // https://www.w3.org/TR/2012/WD-css3-conditional-20120911/#url-of-doc
-    // but the spec is outdated and doesn't account for SPA sites
-    // so we only respect it for `url()` function
-    if (section.urls && (
-      section.urls.includes(query.url) ||
-      section.urls.includes(query.urlWithoutHash)
-    )) {
-      return true;
-    }
-    if (section.regexps && section.regexps.some(r => compileRe(r).test(query.url))) {
-      return true;
-    }
     /*
     According to CSS4 @document specification the entire URL must match.
     Stylish-for-Chrome implemented it incorrectly since the very beginning.
     We'll detect styles that abuse the bug by finding the sections that
     would have been applied by Stylish but not by us as we follow the spec.
     */
-    if (section.regexps && section.regexps.some(r => compileSloppyRe(r).test(query.url))) {
+    if (rrL && rr.some(urlMatchRegexpSloppy, query)) {
       return 'sloppy';
     }
     // TODO: check for invalid regexps?
-    return styleSectionGlobal(section);
+    return !rrL && !ppL && !uuL && !ddL &&
+      !query.isOwnPage && // We allow only intentionally targeted sections for own pages
+      (!skipEmptyGlobal || !styleCodeEmpty(section.code));
+  }
+  /** @this {MatchQuery} */
+  function urlMatchDomain(d) {
+    const _d = this.domain;
+    return d === _d ||
+      _d[_d.length - d.length - 1] === '.' && _d.endsWith(d);
+  }
+  /** @this {MatchQuery} */
+  function urlMatchPrefix(p) {
+    return p && this.url.startsWith(p);
+  }
+  /** @this {MatchQuery} */
+  function urlMatchRegexp(r) {
+    return (!this.isOwnPage || /\bextension\b/.test(r)) &&
+      compileRe(r).test(this.url);
+  }
+  /** @this {MatchQuery} */
+  function urlMatchRegexpSloppy(r) {
+    return (!this.isOwnPage || /\bextension\b/.test(r)) &&
+      compileSloppyRe(r).test(this.url);
   }
 
   function createCompiler(compile) {
@@ -674,37 +710,8 @@ const styleMan = (() => {
       '$';
   }
 
-  function createMatchQuery(url) {
-    let urlWithoutHash;
-    let urlWithoutParams;
-    let domain;
-    return {
-      url,
-      get urlWithoutHash() {
-        if (!urlWithoutHash) {
-          urlWithoutHash = url.split('#')[0];
-        }
-        return urlWithoutHash;
-      },
-      get urlWithoutParams() {
-        if (!urlWithoutParams) {
-          const u = tryURL(url);
-          urlWithoutParams = u.origin + u.pathname;
-        }
-        return urlWithoutParams;
-      },
-      get domain() {
-        if (!domain) {
-          const u = tryURL(url);
-          domain = u.hostname;
-        }
-        return domain;
-      },
-    };
-  }
-
   function buildCache(cache, url, styleList) {
-    const query = createMatchQuery(url);
+    const query = new MatchQuery(url);
     for (const {style, appliesTo, preview} of styleList) {
       const code = getAppliedCode(query, preview || style);
       if (code) {
diff --git a/js/sections-util.js b/js/sections-util.js
index 1e21aac1..2d78d78c 100644
--- a/js/sections-util.js
+++ b/js/sections-util.js
@@ -5,7 +5,6 @@
   MozDocMapper
   styleCodeEmpty
   styleJSONseemsValid
-  styleSectionGlobal
   styleSectionsEqual
 */
 
@@ -83,14 +82,6 @@ function styleCodeEmpty(code) {
   return false;
 }
 
-/** Checks if section is global i.e. has no targets at all */
-function styleSectionGlobal(section) {
-  return (!section.regexps || !section.regexps.length) &&
-    (!section.urlPrefixes || !section.urlPrefixes.length) &&
-    (!section.urls || !section.urls.length) &&
-    (!section.domains || !section.domains.length);
-}
-
 /**
  * The sections are checked in successive order because it matters when many sections
  * match the same URL and they have rules with the same CSS specificity