diff --git a/packages/linter/package-lock.json b/packages/linter/package-lock.json
index c9c9909f3..6b7e33c96 100644
--- a/packages/linter/package-lock.json
+++ b/packages/linter/package-lock.json
@@ -170,9 +170,9 @@
 			"integrity": "sha512-klh/kDpwX8hryYL14M9w/xei6vrv6sE8gTHDG7/T/+SEovB/G4ejwcfE/CBzO6Edsu+OETZMZ3wcX/EjUkrl5A=="
 		},
 		"css-what": {
-			"version": "2.1.3",
-			"resolved": "https://registry.npmjs.org/css-what/-/css-what-2.1.3.tgz",
-			"integrity": "sha512-a+EPoD+uZiNfh+5fxw2nO9QwFa6nJe2Or35fGY6Ipw1R3R4AGz1d1TEZrCegvw2YTmZ0jXirGYlzxxpYSHwpEg=="
+			"version": "5.0.1",
+			"resolved": "https://registry.npmjs.org/css-what/-/css-what-5.0.1.tgz",
+			"integrity": "sha512-FYDTSHb/7KXsWICVsxdmiExPjCfRC4qRFBdVwv7Ax9hMnvMmEjP9RfxTEZ3qPZGmADDn2vAKSo9UcN1jKVYscg=="
 		},
 		"currently-unhandled": {
 			"version": "0.4.1",
diff --git a/packages/linter/package.json b/packages/linter/package.json
index 2652dedc9..754780032 100644
--- a/packages/linter/package.json
+++ b/packages/linter/package.json
@@ -15,7 +15,7 @@
     "babel-traverse": "^6.26.0",
     "babel-types": "^6.26.0",
     "cancel-token": "^0.1.1",
-    "css-what": "^2.1.0",
+    "css-what": "^5.0.1",
     "dom5": "^3.0.0",
     "fast-levenshtein": "^2.0.6",
     "parse5": "^4.0.0",