diff --git a/index.js b/index.js
index 89c485f..21ae153 100644
--- a/index.js
+++ b/index.js
@@ -106,7 +106,7 @@ module.exports = function (file, opts) {
         try {
             var undeclared = opts.always
                 ? { identifiers: varNames, properties: [] }
-                : undeclaredIdentifiers(source)
+                : undeclaredIdentifiers(source, { wildcard: true })
             ;
         }
         catch (err) {
diff --git a/package.json b/package.json
index aa16adc..4104128 100644
--- a/package.json
+++ b/package.json
@@ -14,7 +14,7 @@
     "path-is-absolute": "^1.0.1",
     "process": "~0.11.0",
     "through2": "^2.0.0",
-    "undeclared-identifiers": "^1.0.0",
+    "undeclared-identifiers": "^1.1.2",
     "xtend": "^4.0.0"
   },
   "devDependencies": {
diff --git a/test/isbuffer.js b/test/isbuffer.js
index 221e4ce..4ff6819 100644
--- a/test/isbuffer.js
+++ b/test/isbuffer.js
@@ -53,7 +53,7 @@ test('isbuffer (and new Buffer)', function (t) {
         t.equal(c.require('main')('wow'), false, 'is not a buffer');
         t.equal(isBuffer(c.require('main').a()), true, 'is a buffer');
         t.ok(/require\("buffer"\)/.test(src), 'buffer required in source')
-        t.equal(c.require('main').a().toString('hex'), 'abcd', 'is a buffer');
+        t.equal(c.require('main').a().toString('utf8'), 'abcd', 'is a buffer');
     }));
     deps.write({ transform: inserter, global: true });
     deps.end({ id: 'main', file: __dirname + '/isbuffer/new.js' });