diff --git a/lib/os.js b/lib/os.js
index 75a863e2f72d1e..cd4eb1c12f49bc 100644
--- a/lib/os.js
+++ b/lib/os.js
@@ -23,16 +23,20 @@ exports.platform = function() {
 };
 
 exports.tmpdir = function() {
+  var path;
   if (isWindows) {
-    return process.env.TEMP ||
+    path = process.env.TEMP ||
            process.env.TMP ||
            (process.env.SystemRoot || process.env.windir) + '\\temp';
   } else {
-    return process.env.TMPDIR ||
+    path = process.env.TMPDIR ||
            process.env.TMP ||
            process.env.TEMP ||
            '/tmp';
   }
+  if (/[\\\/]$/.test(path))
+    path = path.slice(0, -1);
+  return path;
 };
 
 exports.tmpDir = exports.tmpdir;
diff --git a/test/parallel/test-os.js b/test/parallel/test-os.js
index ae57353435333a..b5f39973a6f71f 100644
--- a/test/parallel/test-os.js
+++ b/test/parallel/test-os.js
@@ -13,6 +13,8 @@ if (process.platform === 'win32') {
   process.env.TMP = '';
   var expected = (process.env.SystemRoot || process.env.windir) + '\\temp';
   assert.equal(os.tmpdir(), expected);
+  process.env.TEMP = '\\temp\\';
+  assert.equal(os.tmpdir(), '\\temp');
 } else {
   assert.equal(os.tmpdir(), '/tmpdir');
   process.env.TMPDIR = '';
@@ -21,6 +23,8 @@ if (process.platform === 'win32') {
   assert.equal(os.tmpdir(), '/temp');
   process.env.TEMP = '';
   assert.equal(os.tmpdir(), '/tmp');
+  process.env.TMPDIR = '/tmpdir/';
+  assert.equal(os.tmpdir(), '/tmpdir');
 }
 
 var endianness = os.endianness();