diff --git a/TypeScript/eslint/package-lock.json b/TypeScript/eslint/package-lock.json
index 25c1aad..9322cdc 100644
--- a/TypeScript/eslint/package-lock.json
+++ b/TypeScript/eslint/package-lock.json
@@ -43,18 +43,44 @@
       "dev": true
     },
     "@typescript-eslint/eslint-plugin": {
-      "version": "2.22.0",
-      "resolved": "https://registry.npmjs.org/@typescript-eslint/eslint-plugin/-/eslint-plugin-2.22.0.tgz",
-      "integrity": "sha512-BvxRLaTDVQ3N+Qq8BivLiE9akQLAOUfxNHIEhedOcg8B2+jY8Rc4/D+iVprvuMX1AdezFYautuGDwr9QxqSxBQ==",
+      "version": "2.21.0",
+      "resolved": "https://registry.npmjs.org/@typescript-eslint/eslint-plugin/-/eslint-plugin-2.21.0.tgz",
+      "integrity": "sha512-b5jjjDMxzcjh/Sbjuo7WyhrQmVJg0WipTHQgXh5Xwx10uYm6nPWqN1WGOsaNq4HR3Zh4wUx4IRQdDkCHwyewyw==",
       "dev": true,
       "requires": {
-        "@typescript-eslint/experimental-utils": "2.22.0",
+        "@typescript-eslint/experimental-utils": "2.21.0",
         "eslint-utils": "^1.4.3",
         "functional-red-black-tree": "^1.0.1",
         "regexpp": "^3.0.0",
         "tsutils": "^3.17.1"
       },
       "dependencies": {
+        "@typescript-eslint/experimental-utils": {
+          "version": "2.21.0",
+          "resolved": "https://registry.npmjs.org/@typescript-eslint/experimental-utils/-/experimental-utils-2.21.0.tgz",
+          "integrity": "sha512-olKw9JP/XUkav4lq0I7S1mhGgONJF9rHNhKFn9wJlpfRVjNo3PPjSvybxEldvCXnvD+WAshSzqH5cEjPp9CsBA==",
+          "dev": true,
+          "requires": {
+            "@types/json-schema": "^7.0.3",
+            "@typescript-eslint/typescript-estree": "2.21.0",
+            "eslint-scope": "^5.0.0"
+          }
+        },
+        "@typescript-eslint/typescript-estree": {
+          "version": "2.21.0",
+          "resolved": "https://registry.npmjs.org/@typescript-eslint/typescript-estree/-/typescript-estree-2.21.0.tgz",
+          "integrity": "sha512-NC/nogZNb9IK2MEFQqyDBAciOT8Lp8O3KgAfvHx2Skx6WBo+KmDqlU3R9KxHONaijfTIKtojRe3SZQyMjr3wBw==",
+          "dev": true,
+          "requires": {
+            "debug": "^4.1.1",
+            "eslint-visitor-keys": "^1.1.0",
+            "glob": "^7.1.6",
+            "is-glob": "^4.0.1",
+            "lodash": "^4.17.15",
+            "semver": "^6.3.0",
+            "tsutils": "^3.17.1"
+          }
+        },
         "regexpp": {
           "version": "3.0.0",
           "resolved": "https://registry.npmjs.org/regexpp/-/regexpp-3.0.0.tgz",
diff --git a/TypeScript/eslint/package.json b/TypeScript/eslint/package.json
index dec3ffc..7fc1fa4 100644
--- a/TypeScript/eslint/package.json
+++ b/TypeScript/eslint/package.json
@@ -4,7 +4,7 @@
   "license": "MIT",
   "dependencies": {},
   "devDependencies": {
-    "@typescript-eslint/eslint-plugin": "^2.22.0",
+    "@typescript-eslint/eslint-plugin": "^2.21.0",
     "@typescript-eslint/parser": "^2.22.0",
     "eslint": "^6.8.0",
     "typescript": "^3.8.3"
diff --git a/TypeScript/eslint/sample/check.ts b/TypeScript/eslint/sample/check.ts
new file mode 100644
index 0000000..6069b9d
--- /dev/null
+++ b/TypeScript/eslint/sample/check.ts
@@ -0,0 +1,18 @@
+export { };
+
+// @typescript-eslint/explicit-function-return-type:off
+function fun_rt() {
+  //
+}
+
+// @typescript-eslint/no-explicit-any:off
+const var_any: any = 1;
+
+// @typescript-eslint/no-non-null-assertion:off
+const var_nna = { prop: 1 } as { prop: number } | null;
+console.log(var_nna!.prop);
+
+// @typescript-eslint/type-annotation-spacing
+const var_tas1: number = Math.random();
+const var_tas2: () => number = Math.random;
+const var_tas3: new () => Error = Error;
diff --git a/TypeScript/eslint/tsconfig.json b/TypeScript/eslint/tsconfig.json
index 875cb60..9647394 100644
--- a/TypeScript/eslint/tsconfig.json
+++ b/TypeScript/eslint/tsconfig.json
@@ -1,3 +1,5 @@
 {
-  "compilerOptions": {}
+  "compilerOptions": {
+    "strictNullChecks": true
+  }
 }