diff --git a/package.json b/package.json
index 93721b5f6..eed6f46dc 100644
--- a/package.json
+++ b/package.json
@@ -126,7 +126,7 @@
     "rimraf": "^3.0.0",
     "semantic-release": "^15.13.28",
     "ts-node": "^8.10.1",
-    "typescript": "^3.5.3"
+    "typescript": "^4.0.0"
   },
   "peerDependencies": {
     "eslint": ">=5"
diff --git a/src/rules/no-focused-tests.ts b/src/rules/no-focused-tests.ts
index eb7cd2610..d0af58d81 100644
--- a/src/rules/no-focused-tests.ts
+++ b/src/rules/no-focused-tests.ts
@@ -30,6 +30,7 @@ const isConcurrentExpression = (
 
 const matchesTestFunction = (object: TSESTree.LeftHandSideExpression) =>
   'name' in object &&
+  typeof object.name === 'string' &&
   (object.name in TestCaseName || object.name in DescribeAlias);
 
 const isCallToFocusedTestFunction = (object: TSESTree.Identifier) =>
diff --git a/yarn.lock b/yarn.lock
index c525e1c5f..646fa5a6a 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -8628,10 +8628,10 @@ typedarray@^0.0.6:
   resolved "https://registry.yarnpkg.com/typedarray/-/typedarray-0.0.6.tgz#867ac74e3864187b1d3d47d996a78ec5c8830777"
   integrity sha1-hnrHTjhkGHsdPUfZlqeOxciDB3c=
 
-typescript@^3.5.3:
-  version "3.9.7"
-  resolved "https://registry.yarnpkg.com/typescript/-/typescript-3.9.7.tgz#98d600a5ebdc38f40cb277522f12dc800e9e25fa"
-  integrity sha512-BLbiRkiBzAwsjut4x/dsibSTB6yWpwT5qWmC2OfuCg3GgVQCSgMs4vEctYPhsaGtd0AeuuHMkjZ2h2WG8MSzRw==
+typescript@^4.0.0:
+  version "4.0.2"
+  resolved "https://registry.yarnpkg.com/typescript/-/typescript-4.0.2.tgz#7ea7c88777c723c681e33bf7988be5d008d05ac2"
+  integrity sha512-e4ERvRV2wb+rRZ/IQeb3jm2VxBsirQLpQhdxplZ2MEzGvDkkMmPglecnNDfSUBivMjP93vRbngYYDQqQ/78bcQ==
 
 uglify-js@^3.1.4:
   version "3.10.0"