diff --git a/index.d.ts b/index.d.ts
new file mode 100644
index 0000000..ac33dc3
--- /dev/null
+++ b/index.d.ts
@@ -0,0 +1,39 @@
+declare module "potpack" {
+  export interface PotpackBox {
+    w: number;
+    h: number;
+    /**
+     * X coordinate in the resulting container.
+     */
+    x?: number;
+    /**
+     * Y coordinate in the resulting container.
+     */
+    y?: number;
+  }
+
+  interface PotpackStats {
+    /**
+     * Width of the resulting container.
+     */
+    w: number;
+    /**
+     * Height of the resulting container.
+     */
+    h: number;
+    /**
+     * The space utilization value (0 to 1). Higher is better.
+     */
+    fill: number;
+  }
+
+  /**
+   * Packs 2D rectangles into a near-square container.
+   *
+   * Mutates the {@link boxes} array: it's sorted by height,
+   * and box objects are augmented with `x`, `y` coordinates.
+   */
+  const potpack: (boxes: PotpackBox[]) => PotpackStats;
+
+  export default potpack;
+}
diff --git a/package.json b/package.json
index 62938fe..50195f1 100644
--- a/package.json
+++ b/package.json
@@ -6,6 +6,7 @@
   "module": "index.mjs",
   "unpkg": "index.js",
   "jsdelivr": "index.js",
+  "types": "index.d.ts",
   "files": [
     "index.mjs",
     "index.js"