diff --git a/lib/main.js b/lib/main.js
index c7178d3..6e27891 100644
--- a/lib/main.js
+++ b/lib/main.js
@@ -75,12 +75,24 @@ const generateInvalidPointTrace = async (execPath, match, filePath, textEditor,
 
 export default {
   activate() {
-    require('atom-package-deps').install('linter-flake8');
+    this.idleCallbacks = new Set();
 
-    // FIXME: Remove after a few versions
-    if (typeof atom.config.get('linter-flake8.disableTimeout') !== 'undefined') {
-      atom.config.unset('linter-flake8.disableTimeout');
-    }
+    let packageDepsID;
+    const linterFlake8Deps = () => {
+      this.idleCallbacks.delete(packageDepsID);
+
+      // Request checking / installation of package dependencies
+      if (!atom.inSpecMode()) {
+        require('atom-package-deps').install('linter-flake8');
+      }
+
+      // FIXME: Remove after a few versions
+      if (typeof atom.config.get('linter-flake8.disableTimeout') !== 'undefined') {
+        atom.config.unset('linter-flake8.disableTimeout');
+      }
+    };
+    packageDepsID = window.requestIdleCallback(linterFlake8Deps);
+    this.idleCallbacks.add(packageDepsID);
 
     this.subscriptions = new CompositeDisposable();
     this.subscriptions.add(
@@ -118,6 +130,8 @@ export default {
   },
 
   deactivate() {
+    this.idleCallbacks.forEach(callbackID => window.cancelIdleCallback(callbackID));
+    this.idleCallbacks.clear();
     this.subscriptions.dispose();
   },
 
diff --git a/package.json b/package.json
index b0282de..03e20a8 100644
--- a/package.json
+++ b/package.json
@@ -113,7 +113,8 @@
       "atom": true
     },
     "env": {
-      "node": true
+      "node": true,
+      "browser": true
     }
   },
   "providedServices": {