diff --git a/index.d.ts b/index.d.ts
index 861793d..fccc7a6 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -1 +1,92 @@
-define module 'csv-string';
+declare module "csv-string" {
+  import { Transform } from "stream";
+
+  namespace CsvString {
+    type rowElement = string | number | boolean;
+
+    type row = rowElement[];
+
+    type separator = "," | ";" | "|" | "\t";
+
+    function parse(input: string, separator?: separator, quote?: string): row;
+
+    function stringify(input: row, separator?: string): string;
+
+    function detect(input: string): separator;
+
+    function createStream(options?: {
+      separator: separator;
+      quote: string;
+    }): Transform;
+
+    type forEachCallback = (row: row, index: number) => undefined;
+
+    function forEach(
+      input: string,
+      separator: string,
+      quote: string,
+      callback: forEachCallback
+    ): void;
+
+    function forEach(
+      input: string,
+      separator: string,
+      callback: forEachCallback
+    ): void;
+
+    function forEach(input: string, callback: forEachCallback): void;
+
+    type readCallback = (row: row) => undefined;
+
+    function read(
+      input: string,
+      separator: string,
+      quote: string,
+      callback: readCallback
+    ): number;
+
+    function read(
+      input: string,
+      separator: string,
+      callback: readCallback
+    ): number;
+
+    function read(input: string, callback: readCallback): number;
+
+    type readAllCallback = readCallback;
+
+    function readAll(
+      input: string,
+      separator: string,
+      quote: string,
+      callback: readCallback
+    ): number;
+
+    function readAll(
+      input: string,
+      separator: string,
+      callback: readCallback
+    ): number;
+
+    function readAll(input: string, callback: readCallback): number;
+
+    type readChunkCallback = readCallback;
+
+    function readChunk(
+      input: string,
+      separator: string,
+      quote: string,
+      callback: readCallback
+    ): number;
+
+    function readChunk(
+      input: string,
+      separator: string,
+      callback: readCallback
+    ): number;
+
+    function readChunk(input: string, callback: readCallback): number;
+  }
+
+  export = CsvString;
+}