diff --git a/_locales/en/messages.json b/_locales/en/messages.json
index db137368..c9fb1aa6 100644
--- a/_locales/en/messages.json
+++ b/_locales/en/messages.json
@@ -1530,6 +1530,10 @@
     "message": "The value cannot be saved. Try reducing the amount of text.",
     "description": "Displayed when trying to save an excessively big value via storage.sync API"
   },
+  "syncError": {
+    "message": "Sync failed",
+    "description": "Tooltip for the toolbar icon"
+  },
   "syncErrorRelogin": {
     "message": "Sync failed.\nTry to re-login in Stylus options:\nclick 'disconnect' first, then 'connect'.",
     "description": "Tooltip for the toolbar icon"
diff --git a/background/sync-manager.js b/background/sync-manager.js
index c680898d..db816a1e 100644
--- a/background/sync-manager.js
+++ b/background/sync-manager.js
@@ -27,6 +27,7 @@ const syncMan = (() => {
     errorMessage: null,
     login: false,
   };
+  let lastError = null;
   let ctrl;
   let currentDrive;
   /** @type {Promise|boolean} will be `true` to avoid wasting a microtask tick on each `await` */
@@ -100,8 +101,10 @@ const syncMan = (() => {
         }
         await syncMan.syncNow();
         status.errorMessage = null;
+        lastError = null;
       } catch (err) {
         status.errorMessage = err.message;
+        lastError = err;
         // FIXME: should we move this logic to options.js?
         if (!fromPref) {
           console.error(err);
@@ -139,8 +142,10 @@ const syncMan = (() => {
       try {
         await (ctrl.isInit() ? ctrl.syncNow() : ctrl.start()).catch(handle401Error);
         status.errorMessage = null;
+        lastError = null;
       } catch (err) {
         status.errorMessage = err.message;
+        lastError = err;
       }
       emitStatusChange();
     },
@@ -188,27 +193,48 @@ const syncMan = (() => {
   }
 
   async function handle401Error(err) {
-    let emit;
+    let authError = false;
     if (err.code === 401) {
       await tokenMan.revokeToken(currentDrive.name).catch(console.error);
-      emit = true;
+      authError = true;
     } else if (/User interaction required|Requires user interaction/i.test(err.message)) {
-      emit = true;
+      authError = true;
     }
-    if (emit) {
+    if (authError) {
       status.login = false;
       emitStatusChange();
     }
-    iconMan.overrideBadge(!emit ? {} : {
-      text: 'x',
-      color: '#F00',
-      title: chrome.i18n.getMessage('syncErrorRelogin'),
-    });
     return Promise.reject(err);
   }
 
   function emitStatusChange() {
     msg.broadcastExtension({method: 'syncStatusUpdate', status});
+
+    if (status.state !== STATES.connected || !lastError || isNetworkError(lastError)) {
+      iconMan.overrideBadge({});
+    } else if (isGrantError(lastError)) {
+      iconMan.overrideBadge({
+        text: 'x',
+        color: '#F00',
+        title: chrome.i18n.getMessage('syncErrorRelogin'),
+      });
+    } else {
+      iconMan.overrideBadge({
+        text: 'x',
+        color: '#F00',
+        title: chrome.i18n.getMessage('syncError'),
+      });
+    }
+  }
+
+  function isNetworkError(err) {
+    return err.name === 'TypeError' && /networkerror|failed to fetch/i.test(err.message);
+  }
+
+  function isGrantError(err) {
+    if (err.code === 401) return true;
+    if (err.code === 400 && /invalid_grant/.test(err.message)) return true;
+    return false;
   }
 
   function getDrive(name) {
diff --git a/package-lock.json b/package-lock.json
index 6abf6ec6..9fce00ac 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -645,7 +645,6 @@
         "espree": "7.3.0",
         "esprima": "4.0.1",
         "fluent-syntax": "0.13.0",
-        "fsevents": "2.2.1",
         "glob": "7.1.6",
         "is-mergeable-object": "1.1.1",
         "jed": "1.1.1",
@@ -1855,12 +1854,6 @@
       "engines": [
         "node >=0.10.0"
       ],
-      "dependencies": {
-        "dtrace-provider": "~0.8",
-        "moment": "^2.19.3",
-        "mv": "~2",
-        "safe-json-stringify": "~1"
-      },
       "bin": {
         "bunyan": "bin/bunyan"
       },
@@ -2144,7 +2137,6 @@
       "dependencies": {
         "anymatch": "~3.1.1",
         "braces": "~3.0.2",
-        "fsevents": "~2.1.2",
         "glob-parent": "~5.1.0",
         "is-binary-path": "~2.1.0",
         "is-glob": "~4.0.1",
@@ -4559,9 +4551,6 @@
       "resolved": "https://registry.npmjs.org/jsonfile/-/jsonfile-4.0.0.tgz",
       "integrity": "sha1-h3Gq4HmbZAdrdmQPygWPnBDjPss=",
       "dev": true,
-      "dependencies": {
-        "graceful-fs": "^4.1.6"
-      },
       "optionalDependencies": {
         "graceful-fs": "^4.1.6"
       }
@@ -6995,7 +6984,6 @@
       "integrity": "sha512-ssHt0dkljEDaKmTgQ04DQgx2ag6G2gMPxA5hpcsoeTbfDgRf2fC2gNSRc6kISjD7ckCpHwwQvXxuTBK8402fXg==",
       "dev": true,
       "dependencies": {
-        "encoding": "^0.1.12",
         "minipass": "^3.1.0",
         "minipass-pipeline": "^1.2.2",
         "minipass-sized": "^1.0.3",
@@ -11284,10 +11272,8 @@
       "integrity": "sha512-aWAgTW4MoSJzZPAicljkO1hsi1oKj/RRq/OJQh2PKI2UKL04c2Bs+MBOB+BBABHTXJpf9mCwHN7ANCvYsvY2sg==",
       "dev": true,
       "dependencies": {
-        "chokidar": "^3.4.1",
         "graceful-fs": "^4.1.2",
-        "neo-async": "^2.5.0",
-        "watchpack-chokidar2": "^2.0.0"
+        "neo-async": "^2.5.0"
       },
       "optionalDependencies": {
         "chokidar": "^3.4.1",
@@ -11371,7 +11357,6 @@
         "anymatch": "^2.0.0",
         "async-each": "^1.0.1",
         "braces": "^2.3.2",
-        "fsevents": "^1.2.7",
         "glob-parent": "^3.1.0",
         "inherits": "^2.0.3",
         "is-binary-path": "^1.0.0",