diff --git a/index.js b/index.js
index 4c0da31..9368b6c 100644
--- a/index.js
+++ b/index.js
@@ -1,6 +1,6 @@
 var assert = require('assert')
 var crypto = require('crypto')
-var pbkdf2 = require('pbkdf2-compat')
+var pbkdf2 = require('pbkdf2-compat').pbkdf2Sync
 
 var DEFAULT_WORDLIST = require('./wordlists/en.json')
 
diff --git a/package.json b/package.json
index 6576857..7c8256c 100644
--- a/package.json
+++ b/package.json
@@ -21,7 +21,7 @@
   },
   "license": "ISC",
   "dependencies": {
-    "pbkdf2-compat": "^1.0.1"
+    "pbkdf2-compat": "2.0.0"
   },
   "devDependencies": {
     "browserify": "^5.9.1",