diff --git a/.eslintignore b/.eslintignore
index a7846d0e5630..d46133ff232a 100644
--- a/.eslintignore
+++ b/.eslintignore
@@ -89,10 +89,8 @@ browser/extensions/pdfjs/content/web**
 # generated or library files in pocket
 browser/extensions/pocket/content/panels/js/tmpl.js
 browser/extensions/pocket/content/panels/js/vendor/**
-# generated or library files in activity-stream
-browser/extensions/activity-stream/data/content/activity-stream.bundle.js
-browser/extensions/activity-stream/test/**
-browser/extensions/activity-stream/vendor/**
+# Activity Stream has incompatible eslintrc. `npm run lint` from its directory
+browser/extensions/activity-stream/**
 # The only file in browser/locales/ is pre-processed.
 browser/locales/**
 # imported from chromium
diff --git a/.flake8 b/.flake8
index dbf5685f0e30..4d7b90c28443 100644
--- a/.flake8
+++ b/.flake8
@@ -5,6 +5,7 @@ max-line-length = 99
 exclude =
     browser/extensions/mortar/ppapi/,
     build/pymake/,
+    node_modules,
     security/nss/,
     testing/mochitest/pywebsocket,
     tools/lint/test/files,
diff --git a/tools/lint/cpp-virtual-final.yml b/tools/lint/cpp-virtual-final.yml
index 319e971ac68b..a5a7f3f8e623 100644
--- a/tools/lint/cpp-virtual-final.yml
+++ b/tools/lint/cpp-virtual-final.yml
@@ -6,6 +6,7 @@ cpp-virtual-final:
     include: ['.']
     exclude:
         # Third-party code with cpp-virtual-final warnings:
+        - '**/node_modules'
         - gfx/angle
         - gfx/skia
         - media/webrtc/trunk