diff --git a/lib/index.js b/lib/index.js
index ac6e97b..ca3913d 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -197,14 +197,14 @@ const Channel = function(length = 0) {
       },
 
       map: (callbackfn, thisArg) => {
-        const output = Channel(length);
+        const output = Channel();
 
         (async () => {
           await readOnly.forEach(value =>
             output.push(callbackfn.call(thisArg, value))
           );
 
-          output.close();
+          await output.close();
         })();
 
         return output;
diff --git a/test/index.js b/test/index.js
index b46ee81..8ae24c7 100644
--- a/test/index.js
+++ b/test/index.js
@@ -271,7 +271,6 @@ describe(`Channel object`, function() {
     await channel.push(`c`);
     await channel.close();
     const mapped = channel.map(value => value.toUpperCase());
-    assert.equal(mapped.length, channel.length);
     assert.deepEqual(await mapped.values(), [`A`, `B`, `C`]);
   });