diff --git a/lib/http-server.js b/lib/http-server.js
index 3dc23f3a..69c5d6ca 100644
--- a/lib/http-server.js
+++ b/lib/http-server.js
@@ -139,7 +139,7 @@ function createKeys (cb) {
       }
 
       var opts = {
-        days: 2048,
+        keySize: 2048,
         algorithm: 'sha256',
         extensions: [
           {