diff --git a/types/koa-generic-session/index.d.ts b/types/koa-generic-session/index.d.ts
new file mode 100644
index 0000000000..f3a84e7b20
--- /dev/null
+++ b/types/koa-generic-session/index.d.ts
@@ -0,0 +1,54 @@
+// Type definitions for koa-generic-session 1.x
+// Project: https://github.com/koajs/generic-session
+// Definitions by: Nick Simmons <https://github.com/nsimmons/>
+// Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+
+import * as Koa from "koa";
+
+declare namespace koaSession {
+    interface Session {
+        cookie: any;
+    }
+
+    interface SessionIdStore {
+        get(): any;
+        set(sid: string, session: Session): void;
+        reset(): void;
+    }
+
+    interface SessionStore {
+        (): SessionStore;
+        get(sid: string): any;
+        set(sid: string, session: Session, ttl: number): void;
+        destroy(sid: string): void;
+    }
+
+    interface SessionOptions {
+        key?: string;
+        store?: SessionStore;
+        ttl?: number;
+        prefix?: string;
+        cookie?: {
+            path?: string;
+            rewrite?: boolean;
+            signed?: boolean;
+            maxAge?: number;
+            secure?: boolean;
+            httpOnly?: boolean;
+        };
+        allowEmpty?: boolean;
+        defer?: boolean;
+        reconnectTimeout?: number;
+        rolling?: boolean;
+        sessionIdStore?: SessionIdStore;
+        genSid?(length: number): string;
+        errorHandler?(error: Error, type: string, ctx: Koa.Context): void;
+        valid?(ctx: Koa.Context, session: Session): boolean;
+        beforeSave?(ctx: Koa.Context, session: Session): void;
+    }
+
+    const MemoryStore: SessionStore;
+}
+
+declare function koaSession(options: koaSession.SessionOptions): Koa.Middleware;
+export = koaSession;
diff --git a/types/koa-generic-session/koa-generic-session-tests.ts b/types/koa-generic-session/koa-generic-session-tests.ts
new file mode 100644
index 0000000000..fb8d69b0e0
--- /dev/null
+++ b/types/koa-generic-session/koa-generic-session-tests.ts
@@ -0,0 +1,35 @@
+import * as Koa from "koa";
+import {MemoryStore, Session} from "koa-generic-session";
+import session = require("koa-generic-session");
+
+const app = new Koa();
+
+app.use(session({
+    key: 'sessionKey',
+    store: MemoryStore(),
+    ttl: 60 * 60,
+    prefix: 'a-prefix',
+    cookie: {
+        path: '/test',
+        rewrite: false,
+        signed: false,
+        maxAge: 60 * 60,
+        secure: true,
+        httpOnly: true,
+    },
+    allowEmpty: false,
+    defer: false,
+    reconnectTimeout: 100,
+    rolling: false,
+    sessionIdStore: {
+        get: () => 'something',
+        set: (sid: string, session: Session) => {},
+        reset: () => {}
+    },
+    genSid: (length: number) => 'aSid',
+    errorHandler: (error: Error, type: string, ctx: Koa.Context) => {},
+    valid: (ctx: Koa.Context, session: Session) => true,
+    beforeSave: (ctx: Koa.Context, session: Session) => {}
+}));
+
+app.listen(80);
diff --git a/types/koa-generic-session/tsconfig.json b/types/koa-generic-session/tsconfig.json
new file mode 100644
index 0000000000..b4cf43dab8
--- /dev/null
+++ b/types/koa-generic-session/tsconfig.json
@@ -0,0 +1,22 @@
+{
+    "compilerOptions": {
+        "module": "commonjs",
+        "lib": [
+            "es6"
+        ],
+        "noImplicitAny": true,
+        "noImplicitThis": true,
+        "strictNullChecks": true,
+        "baseUrl": "../",
+        "typeRoots": [
+            "../"
+        ],
+        "types": [],
+        "noEmit": true,
+        "forceConsistentCasingInFileNames": true
+    },
+    "files": [
+        "index.d.ts",
+        "koa-generic-session-tests.ts"
+    ]
+}
\ No newline at end of file
diff --git a/types/koa-generic-session/tslint.json b/types/koa-generic-session/tslint.json
new file mode 100644
index 0000000000..2750cc0197
--- /dev/null
+++ b/types/koa-generic-session/tslint.json
@@ -0,0 +1 @@
+{ "extends": "dtslint/dt.json" }
\ No newline at end of file