diff --git a/types/caseless/caseless-tests.ts b/types/caseless/caseless-tests.ts
new file mode 100644
index 0000000000..2fb16afaad
--- /dev/null
+++ b/types/caseless/caseless-tests.ts
@@ -0,0 +1,40 @@
+import caseless, { Caseless, httpify } from "caseless";
+
+new Caseless(); // $ExpectError
+
+// tslint:disable-next-line: prefer-const
+let c1: Caseless;
+
+caseless(); // $ExpectType Caseless
+caseless({}); // $ExpectType Caseless
+caseless(null); // $ExpectError
+caseless(1); // $ExpectError
+caseless("2"); // $ExpectError
+
+const c2 = caseless();
+
+c2.set({}); // $ExpectType void
+c2.set('foo', 'bar'); // $ExpectType string | false
+c2.set('foo', 'bar', false); // $ExpectType string | false
+c2.set('foo', new Date()); // $ExpectType string | false
+c2.set(10, 'bar'); // $ExpectError
+
+c2.get('foo'); // $ExpectType any
+c2.get(10); // $ExpectError
+
+c2.has('foo'); // $ExpectType string | false
+c2.has(10); // $ExpectError
+
+c2.swap('foo'); // $ExpectType void
+c2.swap(10); // $ExpectError
+
+c2.del('foo'); // $ExpectType boolean
+
+httpify(null, {}); // $ExpectError
+httpify(1, {}); // $ExpectError
+httpify("2", {}); // $ExpectError
+httpify({}, null); // $ExpectError
+httpify({}, 1); // $ExpectError
+httpify({}, "2"); // $ExpectError
+
+httpify({}, {}); // $ExpectType Caseless
diff --git a/types/caseless/index.d.ts b/types/caseless/index.d.ts
new file mode 100644
index 0000000000..db295a8f89
--- /dev/null
+++ b/types/caseless/index.d.ts
@@ -0,0 +1,24 @@
+// Type definitions for caseless 0.12
+// Project: https://github.com/mikeal/caseless
+// Definitions by: downace <https://github.com/downace>
+// Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+// TypeScript Version: 2.2
+
+type KeyType = string;
+type ValueType = any;
+type RawDict = object;
+
+export interface Caseless {
+    set(name: KeyType, value: ValueType, clobber?: boolean): KeyType | false;
+    set(dict: RawDict): void;
+    has(name: KeyType): KeyType | false;
+    get(name: KeyType): ValueType | undefined;
+    swap(name: KeyType): void;
+    del(name: KeyType): boolean;
+}
+
+export function httpify(resp: object, headers: RawDict): Caseless;
+
+declare function caseless(dict?: RawDict): Caseless;
+
+export default caseless;
diff --git a/types/caseless/tsconfig.json b/types/caseless/tsconfig.json
new file mode 100644
index 0000000000..c7dace4424
--- /dev/null
+++ b/types/caseless/tsconfig.json
@@ -0,0 +1,23 @@
+{
+    "compilerOptions": {
+        "module": "commonjs",
+        "lib": [
+            "es6"
+        ],
+        "noImplicitAny": true,
+        "noImplicitThis": true,
+        "strictNullChecks": true,
+        "strictFunctionTypes": true,
+        "baseUrl": "../",
+        "typeRoots": [
+            "../"
+        ],
+        "types": [],
+        "noEmit": true,
+        "forceConsistentCasingInFileNames": true
+    },
+    "files": [
+        "index.d.ts",
+        "caseless-tests.ts"
+    ]
+}
diff --git a/types/caseless/tslint.json b/types/caseless/tslint.json
new file mode 100644
index 0000000000..3db14f85ea
--- /dev/null
+++ b/types/caseless/tslint.json
@@ -0,0 +1 @@
+{ "extends": "dtslint/dt.json" }