diff --git a/bitbake/lib/bb/fetch2/npm.py b/bitbake/lib/bb/fetch2/npm.py
index 15b281fb4f..780f26d37f 100644
--- a/bitbake/lib/bb/fetch2/npm.py
+++ b/bitbake/lib/bb/fetch2/npm.py
@@ -80,6 +80,7 @@ class Npm(FetchMethod):
         if not ud.version:
             raise ParameterError("NPM fetcher requires a version parameter", ud.url)
         ud.bbnpmmanifest = "%s-%s.deps.json" % (ud.pkgname, ud.version)
+        ud.bbnpmmanifest = ud.bbnpmmanifest.replace('/', '-')
         ud.registry = "http://%s" % (ud.url.replace('npm://', '', 1).split(';'))[0]
         prefixdir = "npm/%s" % ud.pkgname
         ud.pkgdatadir = d.expand("${DL_DIR}/%s" % prefixdir)
@@ -92,6 +93,7 @@ class Npm(FetchMethod):
 
         ud.write_tarballs = ((d.getVar("BB_GENERATE_MIRROR_TARBALLS") or "0") != "0")
         ud.mirrortarball = 'npm_%s-%s.tar.xz' % (ud.pkgname, ud.version)
+        ud.mirrortarball = ud.mirrortarball.replace('/', '-')
         ud.fullmirror = os.path.join(d.getVar("DL_DIR"), ud.mirrortarball)
 
     def need_update(self, ud, d):
@@ -133,8 +135,7 @@ class Npm(FetchMethod):
 
     def unpack(self, ud, destdir, d):
         dldir = d.getVar("DL_DIR")
-        depdumpfile = "%s-%s.deps.json" % (ud.pkgname, ud.version)
-        with open("%s/npm/%s" % (dldir, depdumpfile)) as datafile:
+        with open("%s/npm/%s" % (dldir, ud.bbnpmmanifest)) as datafile:
             workobj = json.load(datafile)
         dldir = "%s/%s" % (os.path.dirname(ud.localpath), ud.pkgname)