2 files changed, 9 insertions, 5 deletions
diff --git a/deps/npm/lib/install/deps.js b/deps/npm/lib/install/deps.js
index 4d315ab188..d7081296db 100644
--- a/deps/npm/lib/install/deps.js
+++ b/deps/npm/lib/install/deps.js
@@ -326,14 +326,16 @@ function andForEachChild (load, next) {
   }
 }
 
-function isDepOptional (tree, name) {
+function isDepOptional (tree, name, pkg) {
+  if (pkg.package && pkg.package._optional) return true
   if (!tree.package.optionalDependencies) return false
   if (tree.package.optionalDependencies[name] != null) return true
   return false
 }
 
 var failedDependency = exports.failedDependency = function (tree, name_pkg) {
-  var name, pkg
+  var name
+  var pkg = {}
   if (typeof name_pkg === 'string') {
     name = name_pkg
   } else {
@@ -342,7 +344,7 @@ var failedDependency = exports.failedDependency = function (tree, name_pkg) {
   }
   tree.children = tree.children.filter(noModuleNameMatches(name))
 
-  if (isDepOptional(tree, name)) {
+  if (isDepOptional(tree, name, pkg)) {
     return false
   }
 
diff --git a/deps/npm/lib/install/inflate-shrinkwrap.js b/deps/npm/lib/install/inflate-shrinkwrap.js
index ab1bdd1f19..b70e9576bf 100644
--- a/deps/npm/lib/install/inflate-shrinkwrap.js
+++ b/deps/npm/lib/install/inflate-shrinkwrap.js
@@ -45,14 +45,16 @@ function inflateShrinkwrap (topPath, tree, swdeps, finishInflating) {
         return inflateShrinkwrap(topPath, child, dependencies || {}, next)
       } else {
         var from = sw.from || requested.raw
-        return fetchPackageMetadata(requested, topPath, iferr(next, andAddShrinkwrap(from, dependencies, next)))
+        var optional = sw.optional
+        return fetchPackageMetadata(requested, topPath, iferr(next, andAddShrinkwrap(from, optional, dependencies, next)))
       }
     }
   }
 
-  function andAddShrinkwrap (from, dependencies, next) {
+  function andAddShrinkwrap (from, optional, dependencies, next) {
     return function (pkg) {
       pkg._from = from
+      pkg._optional = optional
       addShrinkwrap(pkg, iferr(next, andAddBundled(pkg, dependencies, next)))
     }
   }