diff --git a/lib/cache/add-local-tarball.js b/lib/cache/add-local-tarball.js
index 7a65b708..6c724bb7 100644
--- a/lib/cache/add-local-tarball.js
+++ b/lib/cache/add-local-tarball.js
@@ -81,11 +81,13 @@ function addLocalTarball (p, pkgData, shasum, cb_) {
   })
 }
 
-function addPlacedTarball (p, name, shasum, cb) {
-  if (!cb) cb = name, name = ""
+function addPlacedTarball (p, pkgData, shasum, cb) {
+  assert(pkgData, "should have package data by now")
+  assert(typeof cb === "function", "cb function required")
+
   getCacheStat(function (er, cs) {
     if (er) return cb(er)
-    return addPlacedTarball_(p, name, cs.uid, cs.gid, shasum, cb)
+    return addPlacedTarball_(p, pkgData, cs.uid, cs.gid, shasum, cb)
   })
 }
 
@@ -122,7 +124,7 @@ function addPlacedTarball (p, name, shasum, cb) {
 //    When the tar and shasum streams both finish, make sure that the shasum
 //    matches dist.shasum, and if not, clean up and bail.
 
-function addPlacedTarball_ (p, name, uid, gid, resolvedSum, cb) {
+function addPlacedTarball_ (p, pkgData, uid, gid, resolvedSum, cb) {
   // now we know it's in place already as .cache/name/ver/package.tgz
   // unpack to .cache/name/ver/package/, read the package.json,
   // and fire cb with the json data.