diff --git a/package-lock.json b/package-lock.json
index c8c6bcc0e..ab571e7e1 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -7320,9 +7320,9 @@
       }
     },
     "typescript": {
-      "version": "3.9.7",
-      "resolved": "https://registry.npmjs.org/typescript/-/typescript-3.9.7.tgz",
-      "integrity": "sha512-BLbiRkiBzAwsjut4x/dsibSTB6yWpwT5qWmC2OfuCg3GgVQCSgMs4vEctYPhsaGtd0AeuuHMkjZ2h2WG8MSzRw==",
+      "version": "4.1.0-dev.20200915",
+      "resolved": "https://registry.npmjs.org/typescript/-/typescript-4.1.0-dev.20200915.tgz",
+      "integrity": "sha512-zpey0vRjTtubK9FnG9AHAiOeAXrxrYUUuPuUisEegnxM/WwiYKx5P9xaP1lx/sMExfzGlQJd0kKq9go0dNLBGw==",
       "dev": true
     },
     "union-value": {
diff --git a/package.json b/package.json
index fa5469c87..fbe23150f 100644
--- a/package.json
+++ b/package.json
@@ -39,7 +39,7 @@
     "eslint-plugin-jest": "^23.18.0",
     "jest": "^26.1.0",
     "standard": "^14.3.4",
-    "typescript": "^3.9.7"
+    "typescript": "^4.1.0-dev.20200915"
   },
   "typings": "typings/index.d.ts",
   "jest": {
diff --git a/typings/index.d.ts b/typings/index.d.ts
index e404ae88d..998ff803b 100644
--- a/typings/index.d.ts
+++ b/typings/index.d.ts
@@ -27,9 +27,21 @@ declare namespace commander {
     from: 'node' | 'electron' | 'user';
   }
 
-  interface Command {
-    [key: string]: any; // options as properties
+  type Strip<S extends string> = S extends `${infer T} ${infer _}` ? T : S;
+
+  type CommandString<S extends string> = S extends `${infer _}--${infer T}` ? Strip<T> : never;
+
+  type CommandType<S extends string, T = string> =
+    S extends `${infer _}[${infer _}]` ? T | boolean :
+    S extends `${infer _}<${infer _}>` ? T :
+    boolean;
 
+  type ParseCommand<S extends string, T = string> =
+    string extends S ? { [key: string]: any } :
+    CommandString<S> extends never ? never :
+    { [K in CommandString<S>]: CommandType<S, T> };
+
+  interface Command {
     args: string[];
 
     commands: Command[];
@@ -171,9 +183,9 @@ declare namespace commander {
      *
      * @returns `this` command for chaining
      */
-    option(flags: string, description?: string, defaultValue?: string | boolean): this;
-    option(flags: string, description: string, regexp: RegExp, defaultValue?: string | boolean): this;
-    option<T>(flags: string, description: string, fn: (value: string, previous: T) => T, defaultValue?: T): this;
+    option<S extends string, T = string>(flags: S, description?: string, defaultValue?: T): this & Partial<ParseCommand<S, T | string>>;
+    option<S extends string, T = string>(flags: S, description: string, regexp: RegExp, defaultValue?: T): this & Partial<ParseCommand<S, T | string>>;
+    option<S extends string, T>(flags: S, description: string, fn: (value: string, previous: T) => T, defaultValue?: T): this & Partial<ParseCommand<S, T>>;
 
     /**
      * Define a required option, which must have a value after parsing. This usually means
@@ -181,9 +193,9 @@ declare namespace commander {
      *
      * The `flags` string should contain both the short and long flags, separated by comma, a pipe or space.
      */
-    requiredOption(flags: string, description?: string, defaultValue?: string | boolean): this;
-    requiredOption(flags: string, description: string, regexp: RegExp, defaultValue?: string | boolean): this;
-    requiredOption<T>(flags: string, description: string, fn: (value: string, previous: T) => T, defaultValue?: T): this;
+    requiredOption<S extends string, T = string>(flags: S, description?: string, defaultValue?: T): this & ParseCommand<S, T | string>;
+    requiredOption<S extends string, T = string>(flags: S, description: string, regexp: RegExp, defaultValue?: T): this & ParseCommand<S, T | string>;
+    requiredOption<S extends string, T>(flags: S, description: string, fn: (value: string, previous: T) => T, defaultValue?: T): this & ParseCommand<S, T>;
 
     /**
      * Whether to store option values as properties on command object,