diff --git a/index.d.ts b/index.d.ts
new file mode 100644
index 0000000..fcfdd49
--- /dev/null
+++ b/index.d.ts
@@ -0,0 +1,7 @@
+declare namespace base62 {
+    export function setCharacterSet(characters: string): void
+    export function encode(number: number): string
+    export function decode(string: string): number
+}
+
+export = base62