diff --git a/index.d.ts b/index.d.ts
new file mode 100644
index 00000000..02c9e5c6
--- /dev/null
+++ b/index.d.ts
@@ -0,0 +1,14 @@
+/// <reference types="node" />
+
+import { Profiler } from 'inspector'
+import { CoverageMapData } from 'istanbul-lib-coverage'
+
+declare class V8ToIstanbul {
+  load(): Promise<void>
+  applyCoverage(blocks: ReadonlyArray<Profiler.FunctionCoverage>): void
+  toIstanbul(): CoverageMapData
+}
+
+declare function v8ToIstanbul(scriptPath: string, wrapperLength?: number): V8ToIstanbul
+
+export = v8ToIstanbul
diff --git a/package-lock.json b/package-lock.json
index 57810cba..aee286dd 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -159,6 +159,17 @@
       "integrity": "sha1-byTuSHMdMRaOpRBhDW3RXl/Jxv8=",
       "dev": true
     },
+    "@types/istanbul-lib-coverage": {
+      "version": "2.0.1",
+      "resolved": "https://registry.npmjs.org/@types/istanbul-lib-coverage/-/istanbul-lib-coverage-2.0.1.tgz",
+      "integrity": "sha512-hRJD2ahnnpLgsj6KWMYSrmXkM3rm2Dl1qkx6IOFD5FnuNPXJIG5L0dhgKXCYTRMGzU4n0wImQ/xfmRc4POUFlg=="
+    },
+    "@types/node": {
+      "version": "12.0.10",
+      "resolved": "https://registry.npmjs.org/@types/node/-/node-12.0.10.tgz",
+      "integrity": "sha512-LcsGbPomWsad6wmMNv7nBLw7YYYyfdYcz6xryKYQhx89c3XXan+8Q6AJ43G5XDIaklaVkK3mE4fCb0SBvMiPSQ==",
+      "dev": true
+    },
     "JSONStream": {
       "version": "1.3.5",
       "resolved": "https://registry.npmjs.org/JSONStream/-/JSONStream-1.3.5.tgz",
diff --git a/package.json b/package.json
index e58d5b91..1fa01645 100644
--- a/package.json
+++ b/package.json
@@ -3,6 +3,7 @@
   "version": "3.1.3",
   "description": "convert from v8 coverage format to istanbul's format",
   "main": "index.js",
+  "types": "index.d.ts",
   "scripts": {
     "snapshot": "TAP_SNAPSHOT=1 tap test/*.js",
     "test": "c8 --reporter=html --reporter=text tap --no-coverage --no-esm test/*.js",
@@ -26,10 +27,12 @@
   "author": "Ben Coe <ben@npmjs.com>",
   "license": "ISC",
   "dependencies": {
+    "@types/istanbul-lib-coverage": "^2.0.1",
     "convert-source-map": "^1.6.0",
     "source-map": "^0.7.3"
   },
   "devDependencies": {
+    "@types/node": "^12.0.10",
     "c8": "^5.0.1",
     "coveralls": "^3.0.4",
     "should": "^13.2.3",