diff --git a/index.d.ts b/index.d.ts
new file mode 100644
index 0000000..ac714c8
--- /dev/null
+++ b/index.d.ts
@@ -0,0 +1,46 @@
+/**
+ * Get the default charset for a MIME type.
+ *
+ * @param {string} mimeType MIME type
+ * @return {string|boolean} the default charset or false if not found
+ */
+export function charset (mimeType: string): string
+
+/**
+ * Create a full Content-Type header given a MIME type or extension.
+ *
+ * @param {string} type MIME type or extension
+ * @return {boolean|string} Content-Type header
+ */
+export function contentType (type: string): string
+
+/**
+ * Get the default extension for a MIME type.
+ *
+ * @param {string} mimeType MIME type
+ * @return {boolean|string} the extension or false if not found
+ */
+export function extension (mimeType: string): string
+
+/**
+ * Lookup the MIME type for a file path/extension.
+ *
+ * @param {string} path
+ * @return {string|boolean} MIME type, or false if not found
+ */
+export function lookup (path: string): string
+
+/**
+ * charsets.lookup redirects to lookup
+ */
+export var charsets: {lookup: (mimeType: string) => string}
+
+/**
+ * File extensions indexed by MIME type
+ */
+export var extensions: { [extension: string]: string };
+
+/**
+ * MIME types indexed by (lower case) file extension
+ */
+export var types: { [contentType: string]: string };
\ No newline at end of file
diff --git a/package.json b/package.json
index c545098..e401722 100644
--- a/package.json
+++ b/package.json
@@ -27,7 +27,8 @@
   "files": [
     "HISTORY.md",
     "LICENSE",
-    "index.js"
+    "index.js",
+    "index.d.ts"
   ],
   "engines": {
     "node": ">= 0.6"