build referer header out of strings only

1 files changed, 2 insertions, 2 deletions

diff --git a/lib/npm.js b/lib/npm.js
index c8965bdc6..63f9be315 100644
--- a/lib/npm.js
+++ b/lib/npm.js
@@ -207,13 +207,13 @@ Object.keys(abbrevs).concat(plumbing).forEach(function addCommand (c) {
       npm.registry.refer = [a].concat(args[0]).map(function (arg) {
         // exclude anything that might be a URL, path, or private module
         // Those things will always have a slash in them somewhere
-        if (arg && arg.match(/\/|\\/)) {
+        if (arg && arg.match && arg.match(/\/|\\/)) {
           return "[REDACTED]"
         } else {
           return arg
         }
       }).filter(function (arg) {
-        return arg
+        return arg && arg.match
       }).join(" ")
 
       cmd.apply(npm, args)