diff --git a/types/mri/index.d.ts b/types/mri/index.d.ts
index d015594de1..c1808211db 100644
--- a/types/mri/index.d.ts
+++ b/types/mri/index.d.ts
@@ -2,12 +2,37 @@
 // Project: https://github.com/lukeed/mri
 // Definitions by: Brendan Forster <https://github.com/shiftkey>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+// TypeScript Version: 2.4
 
 export = mri;
 
-declare function mri(args: any, opts: any): any;
+declare function mri(args: ReadonlyArray<string>, options?: mri.Options): mri.Argv;
 
 declare namespace mri {
     const prototype: {
     };
+
+    /** A string or array of strings */
+    type ArrayOrString = string | ReadonlyArray<string>;
+
+    /** An object with any keys whose values conform to a specific type */
+    interface DictionaryObject<T = any> {
+        [key: string]: T;
+    }
+
+    interface Options {
+        /** Additional aliases for specific flags */
+        alias?: DictionaryObject<ArrayOrString>;
+        /** A flag or array of flags whose values are boolean */
+        boolean?: ArrayOrString;
+        /** Default values for flags */
+        default?: DictionaryObject;
+        string?: ArrayOrString;
+        unknown?: (flag: string) => void;
+    }
+
+    interface Argv extends DictionaryObject {
+        /** anything after `--` or between options */
+        _: ReadonlyArray<string>;
+    }
 }
diff --git a/types/mri/mri-tests.ts b/types/mri/mri-tests.ts
index e69de29bb2..c766587db1 100644
--- a/types/mri/mri-tests.ts
+++ b/types/mri/mri-tests.ts
@@ -0,0 +1,7 @@
+import * as mri from 'mri';
+
+const first = mri(['--foo', 'bar']);
+
+const second = mri(['--foo', 'bar'], {
+  default: { foo: true, baz: 'hello', bat: 42 }
+});
diff --git a/types/mri/tslint.json b/types/mri/tslint.json
index 3db14f85ea..bc2968ccad 100644
--- a/types/mri/tslint.json
+++ b/types/mri/tslint.json
@@ -1 +1,7 @@
-{ "extends": "dtslint/dt.json" }
+{
+  "extends": "dtslint/dt.json",
+  "rules": {
+    "strict-export-declare-modifiers": false,
+    "prefer-method-signature": false
+  }
+}