diff --git a/background/storage.js b/background/storage.js
index 66a0bfd6..7d055f1a 100644
--- a/background/storage.js
+++ b/background/storage.js
@@ -46,7 +46,7 @@ var chromeLocal = {
 var chromeSync = {
   get(options) {
     return new Promise(resolve => {
-      chrome.storage.sync.get(options, data => resolve(data));
+      chrome.storage.sync.get(options, resolve);
     });
   },
   set(data) {
@@ -54,10 +54,15 @@ var chromeSync = {
       chrome.storage.sync.set(data, () => resolve(data));
     });
   },
-  getValue(key) {
+  getLZValue(key) {
     return chromeSync.get(key).then(data => tryJSONparse(LZString.decompressFromUTF16(data[key])));
   },
-  setValue(key, value) {
+  getLZValues(keys) {
+    return chromeSync.get(keys).then(data =>
+      Object.assign({}, ...keys.map(key =>
+        ({[key]: tryJSONparse(LZString.decompressFromUTF16(data[key]))}))));
+  },
+  setLZValue(key, value) {
     return chromeSync.set({[key]: LZString.compressToUTF16(JSON.stringify(value))});
   }
 };
diff --git a/edit.html b/edit.html
index 234725eb..3368a28b 100644
--- a/edit.html
+++ b/edit.html
@@ -187,7 +187,7 @@
           <select id="editor.linter">
             <option value="csslint" selected>CSSLint</option>
             <option value="stylelint">Stylelint</option>
-            <option value="null" i18n-text="genericDisabledLabel"></option>
+            <option value="" i18n-text="genericDisabledLabel"></option>
           </select>
           <span class="linter-settings" i18n-title="linterConfigTooltip">
             <svg id="linter-settings" class="svg-icon settings">
diff --git a/edit/edit.js b/edit/edit.js
index 6558f8d2..71820ffb 100644
--- a/edit/edit.js
+++ b/edit/edit.js
@@ -1,7 +1,7 @@
 /* eslint brace-style: 0, operator-linebreak: 0 */
 /* global CodeMirror parserlib */
 /* global exports css_beautify onDOMscripted */
-/* global CSSLint initLint getLinterConfigForCodeMirror updateLintReport renderLintReport updateLinter */
+/* global CSSLint initLint linterConfig updateLintReport renderLintReport updateLinter */
 'use strict';
 
 let styleId = null;
@@ -161,8 +161,7 @@ function initCodeMirror() {
   const CM = CodeMirror;
   const isWindowsOS = navigator.appVersion.indexOf('Windows') > 0;
   // lint.js is not loaded initially
-  const hasLinter = typeof getLinterConfigForCodeMirror !== 'undefined' ?
-    getLinterConfigForCodeMirror(prefs.get('editor.linter')) : false;
+  const hasLinter = window.linterConfig ? linterConfig.getForCodeMirror() : false;
 
   // CodeMirror miserably fails on keyMap='' so let's ensure it's not
   if (!prefs.get('editor.keyMap')) {
@@ -1955,7 +1954,7 @@ function showCodeMirrorPopup(title, html, options) {
     foldGutter: true,
     gutters: ['CodeMirror-linenumbers', 'CodeMirror-foldgutter', 'CodeMirror-lint-markers'],
     matchBrackets: true,
-    lint: getLinterConfigForCodeMirror(prefs.get('editor.linter')),
+    lint: linterConfig.getForCodeMirror(),
     styleActiveLine: true,
     theme: prefs.get('editor.theme'),
     keyMap: prefs.get('editor.keyMap')
diff --git a/edit/lint-codemirror-helper.js b/edit/lint-codemirror-helper.js
new file mode 100644
index 00000000..d7ed510b
--- /dev/null
+++ b/edit/lint-codemirror-helper.js
@@ -0,0 +1,31 @@
+/* global CodeMirror CSSLint stylelint linterConfig */
+'use strict';
+
+CodeMirror.registerHelper('lint', 'csslint', code =>
+  CSSLint.verify(code, linterConfig.getCurrent('csslint'))
+    .messages.map(message => ({
+      from: CodeMirror.Pos(message.line - 1, message.col - 1),
+      to: CodeMirror.Pos(message.line - 1, message.col),
+      message: message.message + ` (${message.rule.id})`,
+      severity : message.type
+    }))
+);
+
+CodeMirror.registerHelper('lint', 'stylelint', code =>
+  stylelint.lint({
+    code,
+    config: linterConfig.getCurrent('stylelint'),
+  }).then(({results}) => {
+    if (!results[0]) {
+      return [];
+    }
+    return results[0].warnings.map(warning => ({
+      from: CodeMirror.Pos(warning.line - 1, warning.column - 1),
+      to: CodeMirror.Pos(warning.line - 1, warning.column),
+      message: warning.text
+        .replace('Unexpected ', '')
+        .replace(/^./, firstLetter => firstLetter.toUpperCase()),
+      severity : warning.severity
+    }));
+  })
+);
diff --git a/edit/csslint-config.js b/edit/lint-defaults-csslint.js
similarity index 96%
rename from edit/csslint-config.js
rename to edit/lint-defaults-csslint.js
index c48e6e8e..104f767e 100644
--- a/edit/csslint-config.js
+++ b/edit/lint-defaults-csslint.js
@@ -4,7 +4,7 @@
  * CSSLint Config values
  * 0 = disabled; 1 = warning; 2 = error
  */
-window.csslintDefaultConfig = {
+window.linterConfig.defaults.csslint = {
   // Default warnings
   'display-property-grouping': 1,
   'duplicate-properties': 1,
diff --git a/edit/stylelint-config.js b/edit/lint-defaults-stylelint.js
similarity index 98%
rename from edit/stylelint-config.js
rename to edit/lint-defaults-stylelint.js
index 5dc1106c..0b12052c 100644
--- a/edit/stylelint-config.js
+++ b/edit/lint-defaults-stylelint.js
@@ -1,6 +1,6 @@
 'use strict';
 
-window.stylelintDefaultConfig = (defaultSeverity => ({
+window.linterConfig.defaults.stylelint = (defaultSeverity => ({
   // 'sugarss' is a indent-based syntax like Sass or Stylus
   // ref: https://github.com/postcss/postcss#syntaxes
   syntax: 'sugarss',
diff --git a/edit/lint.js b/edit/lint.js
index d3aaf8db..c3dbf56c 100644
--- a/edit/lint.js
+++ b/edit/lint.js
@@ -1,51 +1,141 @@
 /* global CodeMirror messageBox */
 /* global editors makeSectionVisible showCodeMirrorPopup showHelp */
-/* global stylelintDefaultConfig csslintDefaultConfig onDOMscripted injectCSS require */
+/* global onDOMscripted injectCSS require CSSLint stylelint */
 'use strict';
 
+// eslint-disable-next-line no-var
+var linterConfig = {
+  csslint: {},
+  stylelint: {},
+  defaults: {
+    // set in lint-defaults-csslint.js
+    csslint: {},
+    // set in lint-defaults-stylelint.js
+    stylelint: {},
+  },
+  storageName: {
+    csslint: 'editorCSSLintConfig',
+    stylelint: 'editorStylelintConfig',
+  },
+
+  getCurrent(linter = prefs.get('editor.linter')) {
+    return this.fallbackToDefaults(this[linter] || {});
+  },
+
+  getForCodeMirror(linter = prefs.get('editor.linter')) {
+    return CodeMirror.lint && CodeMirror.lint[linter] ? {
+      getAnnotations: CodeMirror.lint[linter],
+      delay: prefs.get('editor.lintDelay'),
+    } : false;
+  },
+
+  fallbackToDefaults(config, linter = prefs.get('editor.linter')) {
+    if (config && Object.keys(config).length) {
+      if (linter === 'stylelint') {
+        // always use default syntax because we don't expose it in config UI
+        config.syntax = this.defaults.stylelint.syntax;
+      }
+      return config;
+    } else {
+      return deepCopy(this.defaults[linter] || {});
+    }
+  },
+
+  setLinter(linter = prefs.get('editor.linter')) {
+    linter = linter.toLowerCase();
+    linter = linter === 'csslint' || linter === 'stylelint' ? linter : '';
+    if (prefs.get('editor.linter') !== linter) {
+      prefs.set('editor.linter', linter);
+    }
+    return linter;
+  },
+
+  findInvalidRules(config, linter = prefs.get('editor.linter')) {
+    const rules = linter === 'stylelint' ? config.rules : config;
+    const allRules = new Set(
+      linter === 'stylelint'
+      ? Object.keys(stylelint.rules)
+      : CSSLint.getRules().map(rule => rule.id)
+    );
+    return Object.keys(rules).filter(rule => !allRules.has(rule));
+  },
+
+  stringify(config = this.getCurrent()) {
+    if (prefs.get('editor.linter') === 'stylelint') {
+      config.syntax = undefined;
+    }
+    return JSON.stringify(config, null, 2)
+      .replace(/,\n\s+\{\n\s+("severity":\s"\w+")\n\s+\}/g, ', {$1}');
+  },
+
+  save(config) {
+    config = this.fallbackToDefaults(config);
+    const linter = prefs.get('editor.linter');
+    this[linter] = config;
+    BG.chromeSync.setLZValue(this.storageName[linter], config);
+    return config;
+  },
+
+  loadAll() {
+    return BG.chromeSync.getLZValues([
+      'editorCSSLintConfig',
+      'editorStylelintConfig',
+    ]).then(data => {
+      this.csslint = this.fallbackToDefaults(data.editorCSSLintConfig, 'csslint');
+      this.stylelint = this.fallbackToDefaults(data.editorStylelintConfig, 'stylelint');
+    });
+  },
+
+  watchStorage() {
+    chrome.storage.onChanged.addListener((changes, area) => {
+      if (area === 'sync') {
+        for (const name of ['editorCSSLintConfig', 'editorStylelintConfig']) {
+          if (name in changes && changes[name].newValue !== changes[name].oldValue) {
+            this.loadAll().then(() => debounce(updateLinter));
+            break;
+          }
+        }
+      }
+    });
+  },
+
+  // this is an event listener so it can't refer to self via 'this'
+  openOnClick() {
+    setupLinterPopup(linterConfig.stringify());
+  },
+
+  showSavedMessage() {
+    $('#help-popup .saved-message').classList.add('show');
+    clearTimeout($('#help-popup .contents').timer);
+    $('#help-popup .contents').timer = setTimeout(() => {
+      // popup may be closed at this point
+      const msg = $('#help-popup .saved-message');
+      if (msg) {
+        msg.classList.remove('show');
+      }
+    }, 2000);
+  },
+};
+
 function initLint() {
   $('#lint-help').addEventListener('click', showLintHelp);
   $('#lint').addEventListener('click', gotoLintIssue);
+  $('#linter-settings').addEventListener('click', linterConfig.openOnClick);
   window.addEventListener('resize', resizeLintReport);
-  $('#linter-settings').addEventListener('click', openStylelintSettings);
 
   // touch devices don't have onHover events so the element we'll be toggled via clicking (touching)
   if ('ontouchstart' in document.body) {
     $('#lint h2').addEventListener('click', toggleLintReport);
   }
-  // initialize storage of linter config
-  BG.chromeSync.getValue('editorStylelintConfig').then(config => setStylelintConfig(config));
-  BG.chromeSync.getValue('editorCSSLintConfig').then(config => setCSSLintConfig(config));
+
+  linterConfig.loadAll();
+  linterConfig.watchStorage();
 }
 
-function setStylelintConfig(config) {
-  // can't use default parameters, because config may be null
-  if (Object.keys(config || []).length === 0 && typeof stylelintDefaultConfig !== 'undefined') {
-    config = deepCopy(stylelintDefaultConfig.rules);
-  }
-  BG.chromeSync.setValue('editorStylelintConfig', config);
-  return config;
-}
-
-function setCSSLintConfig(config) {
-  if (Object.keys(config || []).length === 0 && typeof csslintDefaultConfig !== 'undefined') {
-    config = Object.assign({}, csslintDefaultConfig);
-  }
-  BG.chromeSync.setValue('editorCSSLintConfig', config);
-  return config;
-}
-
-function getLinterConfigForCodeMirror(name) {
-  return CodeMirror.lint && CodeMirror.lint[name] ? {
-    getAnnotations: CodeMirror.lint[name],
-    delay: prefs.get('editor.lintDelay')
-  } : false;
-}
-
-function updateLinter(linter) {
+function updateLinter(linter = prefs.get('editor.linter')) {
   function updateEditors() {
-    const options = getLinterConfigForCodeMirror(linter);
-    CodeMirror.defaults.lint = options === 'null' ? false : options;
+    const options = linterConfig.getForCodeMirror(linter);
+    CodeMirror.defaults.lint = options;
     editors.forEach(cm => {
       // set lint to "null" to disable
       cm.setOption('lint', options);
@@ -58,7 +148,7 @@ function updateLinter(linter) {
   loadSelectedLinter(linter).then(() => {
     updateEditors();
   });
-  $('#linter-settings').style.display = linter === 'null' ? 'none' : 'inline-block';
+  $('#linter-settings').style.display = !linter ? 'none' : 'inline-block';
 }
 
 function updateLintReport(cm, delay) {
@@ -215,7 +305,7 @@ function showLintHelp() {
   let list = '<ul class="rules">';
   let header = '';
   if (linter === 'csslint') {
-    const CSSLintRules = window.CSSLint.getRules();
+    const CSSLintRules = CSSLint.getRules();
     const findCSSLintRule = id => CSSLintRules.find(rule => rule.id === id);
     header = t('linterIssuesHelp', makeLink('https://github.com/CSSLint/csslint/wiki/Rules-by-ID', 'CSSLint'));
     template = ruleID => {
@@ -246,64 +336,27 @@ function showLinterErrorMessage(title, contents) {
   });
 }
 
-function showSavedMessage() {
-  $('#help-popup .saved-message').classList.add('show');
-  clearTimeout($('#help-popup .contents').timer);
-  $('#help-popup .contents').timer = setTimeout(() => {
-    // popup may be closed at this point
-    const msg = $('#help-popup .saved-message');
-    if (msg) {
-      msg.classList.remove('show');
-    }
-  }, 2000);
-}
-
-function checkLinter(linter = prefs.get('editor.linter')) {
-  linter = linter.toLowerCase();
-  if (prefs.get('editor.linter') !== linter) {
-    prefs.set('editor.linter', linter);
-  }
-  return linter;
-}
-
-function checkConfigRules(linter, config) {
-  const invalid = [];
-  const linterRules = linter === 'stylelint'
-    ? Object.keys(window.stylelint.rules)
-    : window.CSSLint.getRules().map(rule => rule.id);
-  Object.keys(config).forEach(setting => {
-    if (!linterRules.includes(setting)) {
-      invalid.push(setting);
-    }
-  });
-  return invalid;
-}
-
-function stringifyConfig(config) {
-  return JSON.stringify(config, null, 2)
-    .replace(/,\n\s+\{\n\s+("severity":\s"\w+")\n\s+\}/g, ', {$1}');
-}
-
 function setupLinterSettingsEvents(popup) {
   $('.save', popup).addEventListener('click', event => {
     event.preventDefault();
-    const linter = checkLinter(event.target.dataset.linter);
+    const linter = linterConfig.setLinter(event.target.dataset.linter);
     const json = tryJSONparse(popup.codebox.getValue());
     if (json) {
-      const invalid = checkConfigRules(linter, json);
+      const invalid = linterConfig.findInvalidRules(json, linter);
       if (invalid.length) {
-        return showLinterErrorMessage(
-          linter,
-          t('linterInvalidConfigError') + `<ul><li>${invalid.join('</li><li>')}</li></ul>`
-        );
+        showLinterErrorMessage(linter, [
+          t('linterInvalidConfigError'),
+          $element({
+            tag: 'ul',
+            appendChild: invalid.map(name =>
+              $element({tag: 'li', textContent: name})),
+          }),
+        ]);
+        return;
       }
-      if (linter === 'stylelint') {
-        setStylelintConfig(json);
-      } else {
-        setCSSLintConfig(json);
-      }
-      updateLinter(linter);
-      showSavedMessage();
+      linterConfig.save(json);
+      linterConfig.showSavedMessage();
+      debounce(updateLinter, 0, linter);
     } else {
       showLinterErrorMessage(linter, t('linterJSONError'));
     }
@@ -311,16 +364,8 @@ function setupLinterSettingsEvents(popup) {
   });
   $('.reset', popup).addEventListener('click', event => {
     event.preventDefault();
-    const linter = checkLinter(event.target.dataset.linter);
-    let config;
-    if (linter === 'stylelint') {
-      setStylelintConfig();
-      config = stylelintDefaultConfig.rules;
-    } else {
-      setCSSLintConfig();
-      config = csslintDefaultConfig;
-    }
-    popup.codebox.setValue(stringifyConfig(config));
+    const linter = linterConfig.setLinter(event.target.dataset.linter);
+    popup.codebox.setValue(linterConfig.stringify(linterConfig.defaults[linter] || {}));
     popup.codebox.focus();
   });
   $('.cancel', popup).addEventListener('click', event => {
@@ -329,23 +374,6 @@ function setupLinterSettingsEvents(popup) {
   });
 }
 
-function openStylelintSettings() {
-  const linter = prefs.get('editor.linter');
-  BG.chromeSync.getValue(
-    linter === 'stylelint'
-      ? 'editorStylelintConfig'
-      : 'editorCSSLintConfig'
-  ).then(config => {
-    if (!config || config.length === 0) {
-      config = linter === 'stylelint'
-        ? setStylelintConfig(config)
-        : setCSSLintConfig(config);
-    }
-    const configString = stringifyConfig(config);
-    setupLinterPopup(configString);
-  });
-}
-
 function setupLinterPopup(config) {
   const linter = prefs.get('editor.linter');
   const linterTitle = linter === 'stylelint' ? 'Stylelint' : 'CSSLint';
@@ -406,26 +434,25 @@ function setupLinterPopup(config) {
 
 function loadSelectedLinter(name) {
   const scripts = [];
-  if (name !== 'null' && !$('script[src*="css-lint.js"]')) {
-    // inject css
-    injectCSS('vendor/codemirror/addon/lint/lint.css');
-    injectCSS('msgbox/msgbox.css');
-    // load CodeMirror lint code
-    scripts.push(
-      'vendor/codemirror/addon/lint/lint.js',
-      'vendor-overwrites/codemirror/addon/lint/css-lint.js',
-      'msgbox/msgbox.js'
-    );
-  }
   if (name === 'csslint' && !window.CSSLint) {
     scripts.push(
-      'edit/csslint-config.js',
-      'vendor-overwrites/csslint/csslint-worker.js'
+      'vendor-overwrites/csslint/csslint-worker.js',
+      'edit/lint-defaults-csslint.js'
     );
   } else if (name === 'stylelint' && !window.stylelint) {
     scripts.push(
       'vendor-overwrites/stylelint/stylelint-bundle.min.js',
-      'edit/stylelint-config.js'
+      () => (window.stylelint = require('stylelint')),
+      'edit/lint-defaults-stylelint.js'
+    );
+  }
+  if (name && !$('script[src$="vendor/codemirror/addon/lint/lint.js"]')) {
+    injectCSS('vendor/codemirror/addon/lint/lint.css');
+    injectCSS('msgbox/msgbox.css');
+    scripts.push(
+      'vendor/codemirror/addon/lint/lint.js',
+      'edit/lint-codemirror-helper.js',
+      'msgbox/msgbox.js'
     );
   }
   return onDOMscripted(scripts);
diff --git a/js/prefs.js b/js/prefs.js
index fdfb2cce..2e47a7bd 100644
--- a/js/prefs.js
+++ b/js/prefs.js
@@ -42,7 +42,7 @@ var prefs = new function Prefs() {
       indent_conditional: true,
     },
     'editor.lintDelay': 500,        // lint gutter marker update delay, ms
-    'editor.linter': 'csslint',     // Choose csslint or stylelint
+    'editor.linter': 'csslint',     // 'csslint' or 'stylelint' or ''
     'editor.lintReportDelay': 4500, // lint report update delay, ms
     'editor.matchHighlight': 'token', // token = token/word under cursor even if nothing is selected
                                       // selection = only when something is selected
diff --git a/vendor-overwrites/codemirror/addon/lint/css-lint.js b/vendor-overwrites/codemirror/addon/lint/css-lint.js
deleted file mode 100644
index b452ae0b..00000000
--- a/vendor-overwrites/codemirror/addon/lint/css-lint.js
+++ /dev/null
@@ -1,114 +0,0 @@
-// CodeMirror, copyright (c) by Marijn Haverbeke and others
-// Distributed under an MIT license: http://codemirror.net/LICENSE
-
-// Depends on csslint.js from https://github.com/stubbornella/csslint
-
-/* global CodeMirror require define */
-/* global CSSLint stylelint stylelintDefaultConfig csslintDefaultConfig */
-'use strict';
-
-(mod => {
-  if (typeof exports === 'object' && typeof module === 'object') {
-    // CommonJS
-    mod(require('../../lib/codemirror'));
-  } else if (typeof define === 'function' && define.amd) {
-    // AMD
-    define(['../../lib/codemirror'], mod);
-  } else {
-    // Plain browser env
-    mod(CodeMirror);
-  }
-})(CodeMirror => {
-  CodeMirror.registerHelper('lint', 'csslint', text => {
-    const found = [];
-    if (!window.CSSLint) {
-      return found;
-    }
-    /* STYLUS: hack start (part 1) */
-    return BG.chromeSync.getValue('editorCSSLintConfig').then(config => {
-      // csslintDefaultConfig stored in csslint-config.js & loaded by edit/lint.js
-      if (Object.keys(config || []).length === 0) {
-        config = Object.assign({}, csslintDefaultConfig);
-      }
-      const results = CSSLint.verify(text, config);
-      const messages = results.messages;
-      const hslRegex = /hsla?\(\s*(-?\d+)%?\s*,\s*(-?\d+)%\s*,\s*(-?\d+|-?\d*.\d+)%(\s*,\s*(-?\d+|-?\d*.\d+))?\s*\)/;
-      let message = null;
-      /* STYLUS: hack end */
-
-      for (let i = 0; i < messages.length; i++) {
-        message = messages[i];
-
-        /* STYLUS: hack start (part 2) */
-        if (message.type === 'warning') {
-           // @font-face {font-family: 'Ampersand'; unicode-range: U+26;}
-          if (message.message.indexOf('unicode-range') !== -1) {
-            continue;
-          } else if (
-            // color: hsl(210, 100%, 2.2%); or color: hsla(210, 100%, 2.2%, 0.3);
-            message.message.startsWith('Expected (<color>) but found \'hsl') &&
-            hslRegex.test(message.message)
-          ) {
-            continue;
-          }
-        }
-        const startLine = message.line - 1;
-        const endLine = message.line - 1;
-        const startCol = message.col - 1;
-        const endCol = message.col;
-        /* STYLUS: hack end */
-
-        found.push({
-          from: CodeMirror.Pos(startLine, startCol),
-          to: CodeMirror.Pos(endLine, endCol),
-          message: message.message + ` (${message.rule.id})`,
-          severity : message.type
-        });
-      }
-      return found;
-    });
-  });
-
-  CodeMirror.registerHelper('lint', 'stylelint', text => {
-    const found = [];
-    window.stylelint = require('stylelint');
-    if (window.stylelint) {
-      return BG.chromeSync.getValue('editorStylelintConfig').then(rules => {
-        // stylelintDefaultConfig stored in stylelint-config.js & loaded by edit/lint.js
-        if (Object.keys(rules || []).length === 0) {
-          rules = stylelintDefaultConfig.rules;
-        }
-        return stylelint.lint({
-          code: text,
-          config: {
-            syntax: stylelintDefaultConfig.syntax,
-            rules: rules
-          }
-        }).then(output => {
-          const warnings = output.results.length ? output.results[0].warnings : [];
-          const len = warnings.length;
-          let warning;
-          let message;
-          if (len) {
-            for (let i = 0; i < len; i++) {
-              warning = warnings[i];
-              message = warning.text
-                .replace('Unexpected ', '')
-                .replace(/^./, function (firstLetter) {
-                  return firstLetter.toUpperCase();
-                });
-              found.push({
-                from: CodeMirror.Pos(warning.line - 1, warning.column - 1),
-                to: CodeMirror.Pos(warning.line - 1, warning.column),
-                message,
-                severity : warning.severity
-              });
-            }
-          }
-          return found;
-        });
-      });
-    }
-    return found;
-  });
-});